diff --git a/phy.go b/phy.go
new file mode 100644
index 0000000..c1d90ad
--- /dev/null
+++ b/phy.go
@@ -0,0 +1,12 @@
+package bluetooth
+
+type PHY uint8
+
+const (
+	// PHY1M is the 1M PHY, which is the default for Bluetooth LE.
+	PHY1M PHY = 0x01
+	// PHY2M is the 2M PHY, which allows for higher data rates but consumes more power.
+	PHY2M PHY = 0x02
+	// PHYCoded is the Coded PHY, which allows for longer range at the cost of lower data rates.
+	PHYCoded PHY = 0x03
+)