The Big Boy 3 speed O-Ring and seal kit includes all necessary O-Rings. We can build a kit for a 2 speed, 4 speed or whatever your needs are. You will need to specify if you are using a clutch or convertor drive as the seals are different. 

Seal kit includes: Inner and Outer piston, endplate, case, reverse hat, reverse case, cross shaft and air passages.  It includes the front and rear seals for the input and output shafts.