diff --git a/usb/constants.go b/usb/constants.go
index e6227ec..c5f8486 100644
--- a/usb/constants.go
+++ b/usb/constants.go
@@ -218,4 +218,14 @@ func (s DeviceSpeed) String() string {
 	return deviceSpeedDescription[s]
 }
 
+const (
+	// SelfPoweredMask is the bitmask for "self powered" field of configuration
+	// descriptor bmAttributes.
+	SelfPoweredMask = 0x40
+	// RemoteWakeupMask is the bitmask for "supports remote wakeup" field of
+	// configuration descriptor bmAttributes.
+	RemoteWakeupMask = 0x20
+)
+
+// Milliamperes is a unit of electric current consumption.
 type Milliamperes uint
diff --git a/usb/descriptor.go b/usb/descriptor.go
index 76a9b77..796ae3d 100644
--- a/usb/descriptor.go
+++ b/usb/descriptor.go
@@ -29,8 +29,8 @@ type Descriptor struct {
 	Product ID // The Product identifier
 
 	// Protocol information
-	Class    uint8 // The class of this device
-	SubClass uint8 // The sub-class (within the class) of this device
+	Class    Class // The class of this device
+	SubClass Class // The sub-class (within the class) of this device
 	Protocol uint8 // The protocol (within the sub-class) of this device
 
 	// Configuration information
diff --git a/usb/libusb.go b/usb/libusb.go
index e1d81b9..4b7b13a 100644
--- a/usb/libusb.go
+++ b/usb/libusb.go
@@ -213,9 +213,11 @@ func (libusbImpl) getDeviceDesc(d *libusbDevice) (*Descriptor, error) {
 			return nil, err
 		}
 		c := ConfigInfo{
-			Config:     uint8(cfg.bConfigurationValue),
-			Attributes: uint8(cfg.bmAttributes),
-			MaxPower:   uint8(cfg.MaxPower),
+			Config:       uint8(cfg.bConfigurationValue),
+			SelfPowered:  (cfg.bmAttributes & SelfPoweredMask) != 0,
+			RemoteWakeup: (cfg.bmAttributes & RemoteWakeupMask) != 0,
+			// TODO(sebek): at GenX speeds MaxPower is expressed in units of 8mA, not 2mA.
+			MaxPower: 2 * Milliamperes(cfg.MaxPower),
 		}
 
 		var ifaces []C.struct_libusb_interface
@@ -274,8 +276,8 @@ func (libusbImpl) getDeviceDesc(d *libusbDevice) (*Descriptor, error) {
 		Device:   BCD(desc.bcdDevice),
 		Vendor:   ID(desc.idVendor),
 		Product:  ID(desc.idProduct),
-		Class:    uint8(desc.bDeviceClass),
-		SubClass: uint8(desc.bDeviceSubClass),
+		Class:    Class(desc.bDeviceClass),
+		SubClass: Class(desc.bDeviceSubClass),
 		Protocol: uint8(desc.bDeviceProtocol),
 		Configs:  cfgs,
 	}, nil
diff --git a/usbid/describe.go b/usbid/describe.go
index 1746a26..1f6c850 100644
--- a/usbid/describe.go
+++ b/usbid/describe.go
@@ -56,12 +56,15 @@ func Describe(val interface{}) string {
 //   - *usb.Descriptor       "Class (SubClass) Protocol"
 //   - usb.InterfaceSetup   "IfClass (IfSubClass) IfProtocol"
 func Classify(val interface{}) string {
-	var class, sub, proto uint8
+	var (
+		class, sub usb.Class
+		proto      uint8
+	)
 	switch val := val.(type) {
 	case *usb.Descriptor:
 		class, sub, proto = val.Class, val.SubClass, val.Protocol
 	case usb.InterfaceSetup:
-		class, sub, proto = val.IfClass, val.IfSubClass, val.IfProtocol
+		class, sub, proto = usb.Class(val.IfClass), usb.Class(val.IfSubClass), val.IfProtocol
 	default:
 		return fmt.Sprintf("Unknown (%T)", val)
 	}
diff --git a/usbid/load.go b/usbid/load.go
index b8dd5d0..65dc8f9 100644
--- a/usbid/load.go
+++ b/usbid/load.go
@@ -34,7 +34,7 @@ var (
 	Vendors map[usb.ID]*Vendor
 
 	// Classes stores the class, subclass and protocol mappings.
-	Classes map[uint8]*Class
+	Classes map[usb.Class]*Class
 )
 
 // LoadFromURL replaces the built-in vendor and class mappings with ones loaded
diff --git a/usbid/parse.go b/usbid/parse.go
index 57571b8..e5a7b38 100644
--- a/usbid/parse.go
+++ b/usbid/parse.go
@@ -52,7 +52,7 @@ func (p Product) String() string {
 // A Class contains the name of the class and mappings for each subclass.
 type Class struct {
 	Name     string
-	SubClass map[uint8]*SubClass
+	SubClass map[usb.Class]*SubClass
 }
 
 // String returns the name of the class.
@@ -75,9 +75,9 @@ func (s SubClass) String() string {
 // should not be necessary, as a set of mappings is already embedded in the library.
 // If a new or specialized file is obtained, this can be used to retrieve the mappings,
 // which can be stored in the global Vendors and Classes map.
-func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, map[uint8]*Class, error) {
+func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, map[usb.Class]*Class, error) {
 	vendors := make(map[usb.ID]*Vendor, 2800)
-	classes := make(map[uint8]*Class) // TODO(kevlar): count
+	classes := make(map[usb.Class]*Class) // TODO(kevlar): count
 
 	split := func(s string) (kind string, level int, id uint64, name string, err error) {
 		pieces := strings.SplitN(s, "  ", 2)
@@ -159,15 +159,13 @@ func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, map[uint8]*Class, error) {
 	var class *Class
 	var subclass *SubClass
 
-	parseClass := func(level int, raw uint64, name string) error {
-		id := uint8(raw)
-
+	parseClass := func(level int, id uint64, name string) error {
 		switch level {
 		case 0:
 			class = &Class{
 				Name: name,
 			}
-			classes[id] = class
+			classes[usb.Class(id)] = class
 
 		case 1:
 			if class == nil {
@@ -178,9 +176,9 @@ func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, map[uint8]*Class, error) {
 				Name: name,
 			}
 			if class.SubClass == nil {
-				class.SubClass = make(map[uint8]*SubClass)
+				class.SubClass = make(map[usb.Class]*SubClass)
 			}
-			class.SubClass[id] = subclass
+			class.SubClass[usb.Class(id)] = subclass
 
 		case 2:
 			if subclass == nil {
@@ -190,7 +188,7 @@ func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, map[uint8]*Class, error) {
 			if subclass.Protocol == nil {
 				subclass.Protocol = make(map[uint8]string)
 			}
-			subclass.Protocol[id] = name
+			subclass.Protocol[uint8(id)] = name
 
 		default:
 			return fmt.Errorf("too many levels of nesting for class")
diff --git a/usbid/testdata_test.go b/usbid/testdata_test.go
index 91c8941..7b6f0fe 100644
--- a/usbid/testdata_test.go
+++ b/usbid/testdata_test.go
@@ -46,13 +46,13 @@ var (
 			},
 		},
 	}
-	testDBClasses = map[uint8]*Class{
+	testDBClasses = map[usb.Class]*Class{
 		0x00: {
 			Name: "(Defined at Interface level)",
 		},
 		0x01: {
 			Name: "Audio",
-			SubClass: map[uint8]*SubClass{
+			SubClass: map[usb.Class]*SubClass{
 				0x01: {Name: "Control Device"},
 				0x02: {Name: "Streaming"},
 				0x03: {Name: "MIDI Streaming"},
@@ -60,7 +60,7 @@ var (
 		},
 		0x02: {
 			Name: "Communications",
-			SubClass: map[uint8]*SubClass{
+			SubClass: map[usb.Class]*SubClass{
 				0x01: {Name: "Direct Line"},
 				0x02: {
 					Name: "Abstract (modem)",