diff --git a/lifx-lan.cabal b/lifx-lan.cabal
--- a/lifx-lan.cabal
+++ b/lifx-lan.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               lifx-lan
-version:            0.5.1.1
+version:            0.6
 license:            BSD-3-Clause
 license-file:       LICENSE
 author:             George Thomas
@@ -18,6 +18,7 @@
     exposed-modules:
         Lifx.Internal.Product
         Lifx.Internal.ProductInfo
+        Lifx.Internal.ProductInfoMap
         Lifx.Lan
     hs-source-dirs: src
     ghc-options:
diff --git a/src/Lifx/Internal/ProductInfoMap.hs b/src/Lifx/Internal/ProductInfoMap.hs
new file mode 100644
--- /dev/null
+++ b/src/Lifx/Internal/ProductInfoMap.hs
@@ -0,0 +1,127 @@
+module Lifx.Internal.ProductInfoMap where
+
+import Control.Applicative
+import Data.Either.Extra
+import Data.Foldable hiding (product)
+import Data.Function
+import Data.Functor
+import Data.Maybe
+import Data.Tuple.Extra
+import Data.Word
+
+import Data.Map (Map, (!?))
+import Data.Map.Strict qualified as Map
+import Data.Text (Text)
+import GHC.Generics (Generic)
+
+import Lifx.Internal.Product
+import Lifx.Internal.ProductInfo
+
+--TODO RecordDotSyntax can make this and other hiding unnecessary (we could also use "id" instead of "productId"...)
+import Prelude hiding (product)
+
+productInfoMap :: Map Word32 (Features, Map Word32 ProductInfo)
+productInfoMap =
+    Map.fromList $
+        productInfo <&> \VendorInfo{..} ->
+            ( vid
+            ,
+                ( defaults
+                , Map.fromList $ (pid &&& id) <$> products
+                )
+            )
+
+-- | Information about a particular LIFX product.
+data Product = Product
+    { name :: Text
+    , productId :: Word32
+    , features :: Features
+    }
+    deriving (Eq, Ord, Show, Generic)
+
+data ProductLookupError
+    = UnknownVendorId Word32
+    | UnknownProductId Word32
+    deriving (Eq, Ord, Show, Generic)
+
+productLookup :: Word32 -> Word32 -> Word16 -> Word16 -> Either ProductLookupError Product
+productLookup vendor product versionMinor versionMajor =
+    case productInfoMap !? vendor of
+        Nothing -> Left $ UnknownVendorId vendor
+        Just (defaults, products) -> case products !? product of
+            Nothing -> Left $ UnknownProductId product
+            Just ProductInfo{features = originalFeatures, ..} ->
+                pure
+                    Product
+                        { name
+                        , productId = product
+                        , features =
+                            completeFeatures defaults $
+                                foldl
+                                    ( \old Upgrade{..} ->
+                                        if (versionMajor, versionMinor) >= (major, minor)
+                                            then addFeatures features old
+                                            else old
+                                    )
+                                    originalFeatures
+                                    upgrades
+                        }
+  where
+    --TODO RecordDotSyntax
+    completeFeatures
+        Features
+            { ..
+            }
+        PartialFeatures
+            { hev = maybe_hev
+            , color = maybe_color
+            , chain = maybe_chain
+            , matrix = maybe_matrix
+            , relays = maybe_relays
+            , buttons = maybe_buttons
+            , infrared = maybe_infrared
+            , multizone = maybe_multizone
+            , temperatureRange = maybe_temperatureRange
+            , extendedMultizone = maybe_extendedMultizone
+            } =
+            Features
+                { hev = fromMaybe hev maybe_hev
+                , color = fromMaybe color maybe_color
+                , chain = fromMaybe chain maybe_chain
+                , matrix = fromMaybe matrix maybe_matrix
+                , relays = fromMaybe relays maybe_relays
+                , buttons = fromMaybe buttons maybe_buttons
+                , infrared = fromMaybe infrared maybe_infrared
+                , multizone = fromMaybe multizone maybe_multizone
+                , temperatureRange = maybe_temperatureRange <|> temperatureRange
+                , extendedMultizone = fromMaybe extendedMultizone maybe_extendedMultizone
+                }
+    -- left-biased
+    addFeatures
+        PartialFeatures
+            { ..
+            }
+        PartialFeatures
+            { hev = old_hev
+            , color = old_color
+            , chain = old_chain
+            , matrix = old_matrix
+            , relays = old_relays
+            , buttons = old_buttons
+            , infrared = old_infrared
+            , multizone = old_multizone
+            , temperatureRange = old_temperatureRange
+            , extendedMultizone = old_extendedMultizone
+            } =
+            PartialFeatures
+                { hev = hev <|> old_hev
+                , color = color <|> old_color
+                , chain = chain <|> old_chain
+                , matrix = matrix <|> old_matrix
+                , relays = relays <|> old_relays
+                , buttons = buttons <|> old_buttons
+                , infrared = infrared <|> old_infrared
+                , multizone = multizone <|> old_multizone
+                , temperatureRange = temperatureRange <|> old_temperatureRange
+                , extendedMultizone = extendedMultizone <|> old_extendedMultizone
+                }
diff --git a/src/Lifx/Lan.hs b/src/Lifx/Lan.hs
--- a/src/Lifx/Lan.hs
+++ b/src/Lifx/Lan.hs
@@ -31,6 +31,7 @@
     LifxT (LifxT),
     runLifxT,
     LifxError (..),
+    ProductLookupError (..),
     MonadLifx (..),
 
     -- * Responses
@@ -97,9 +98,8 @@
 import Data.ByteString qualified as BS
 import Data.ByteString.Lazy qualified as BL
 import Data.List.NonEmpty (NonEmpty)
-import Data.Map (Map, (!?))
+import Data.Map (Map)
 import Data.Map.Strict qualified as Map
-import Data.Text (Text)
 import Data.Time (
     NominalDiffTime,
     diffUTCTime,
@@ -128,7 +128,7 @@
 import System.Timeout (timeout)
 
 import Lifx.Internal.Product
-import Lifx.Internal.ProductInfo
+import Lifx.Internal.ProductInfoMap
 
 --TODO RecordDotSyntax can make this and other hiding unnecessary (we could also use "id" instead of "productId"...)
 import Prelude hiding (product)
@@ -280,8 +280,7 @@
     | WrongSender Device HostAddress -- expected, then actual
     | UnexpectedSockAddrType SockAddr
     | UnexpectedPort PortNumber
-    | UnknownVendorId Word32
-    | UnknownProductId Word32
+    | ProductLookupError ProductLookupError
     deriving (Eq, Ord, Show, Generic)
 
 {- Message responses -}
@@ -663,111 +662,12 @@
         putWord16le if b then maxBound else minBound
         putWord32le $ nominalDiffTimeToInt @Milli d
 
-{- Product info -}
-
-productInfoMap :: Map Word32 (Features, Map Word32 ProductInfo)
-productInfoMap =
-    Map.fromList $
-        productInfo <&> \VendorInfo{..} ->
-            ( vid
-            ,
-                ( defaults
-                , Map.fromList $ (pid &&& id) <$> products
-                )
-            )
-
--- | Information about a particular LIFX product.
-data Product = Product
-    { name :: Text
-    , productId :: Word32
-    , features :: Features
-    }
-    deriving (Eq, Ord, Show, Generic)
-
 -- | Ask a device for its vendor and product ID, and look up info on it from the official database.
 getProductInfo :: MonadLifx m => Device -> m Product
 getProductInfo dev = do
     StateHostFirmware{..} <- sendMessage dev GetHostFirmware
     StateVersion{..} <- sendMessage dev GetVersion
-    case productInfoMap !? vendor of
-        Nothing -> lifxThrow $ UnknownVendorId vendor
-        Just (defaults, products) -> case products !? product of
-            Nothing -> lifxThrow $ UnknownProductId product
-            Just ProductInfo{features = originalFeatures, ..} ->
-                pure
-                    Product
-                        { name
-                        , productId = product
-                        , features =
-                            completeFeatures defaults $
-                                foldl
-                                    ( \old Upgrade{..} ->
-                                        if (versionMajor, versionMinor) >= (major, minor)
-                                            then addFeatures features old
-                                            else old
-                                    )
-                                    originalFeatures
-                                    upgrades
-                        }
-  where
-    --TODO RecordDotSyntax
-    completeFeatures
-        Features
-            { ..
-            }
-        PartialFeatures
-            { hev = maybe_hev
-            , color = maybe_color
-            , chain = maybe_chain
-            , matrix = maybe_matrix
-            , relays = maybe_relays
-            , buttons = maybe_buttons
-            , infrared = maybe_infrared
-            , multizone = maybe_multizone
-            , temperatureRange = maybe_temperatureRange
-            , extendedMultizone = maybe_extendedMultizone
-            } =
-            Features
-                { hev = fromMaybe hev maybe_hev
-                , color = fromMaybe color maybe_color
-                , chain = fromMaybe chain maybe_chain
-                , matrix = fromMaybe matrix maybe_matrix
-                , relays = fromMaybe relays maybe_relays
-                , buttons = fromMaybe buttons maybe_buttons
-                , infrared = fromMaybe infrared maybe_infrared
-                , multizone = fromMaybe multizone maybe_multizone
-                , temperatureRange = maybe_temperatureRange <|> temperatureRange
-                , extendedMultizone = fromMaybe extendedMultizone maybe_extendedMultizone
-                }
-    -- left-biased
-    addFeatures
-        PartialFeatures
-            { ..
-            }
-        PartialFeatures
-            { hev = old_hev
-            , color = old_color
-            , chain = old_chain
-            , matrix = old_matrix
-            , relays = old_relays
-            , buttons = old_buttons
-            , infrared = old_infrared
-            , multizone = old_multizone
-            , temperatureRange = old_temperatureRange
-            , extendedMultizone = old_extendedMultizone
-            } =
-            PartialFeatures
-                { hev = hev <|> old_hev
-                , color = color <|> old_color
-                , chain = chain <|> old_chain
-                , matrix = matrix <|> old_matrix
-                , relays = relays <|> old_relays
-                , buttons = buttons <|> old_buttons
-                , infrared = infrared <|> old_infrared
-                , multizone = multizone <|> old_multizone
-                , temperatureRange = temperatureRange <|> old_temperatureRange
-                , extendedMultizone = extendedMultizone <|> old_extendedMultizone
-                }
+    either (lifxThrow . ProductLookupError) pure $ productLookup vendor product versionMinor versionMajor
 
 {- Util -}