Shaft Size: 5/8" with 3/16" Keyway Suitable for # 35 chain 12T or #40/41/420 Chain 10T 10T Sprocket OR 12T Sprocket (Both included) Includes All Mounting Hardware Forward Ratio: 1:1:3 Reverse Ratio: 1:2:6 Kit Includes: Forward / Reverse Gearbox (2) Mounting Plates Shifter Assembly Shifter Disc (2) Shifter Cable 10T and 12T Sprocket Included 3/16" Keyway Also Fits Manco Go Karts This kit has everything you will need!!