Kit contains everything needed to rebuild your CP reg good as new. To identify which generation regulator you have: Gen1 has a 3-piece body and has flats milled around the bottom of the reg. Gen2 has a 3-piece body and has v-grooves milled around the bottom of the reg. Gen3 is the current model, which has a 2-piece body. Gen3 only comes in one standard piston pressure, 0-500psi.