This TIF KT3307 PROMAX piston compressor rebuild kit includes all parts needed to rebuild the new style (Rectangle Cylinder Only) compressors on RG54XX series, MiniMax Series and PROVAC Compressors. This kit will not repair round cylinder compressors, if you have a round cylinder compressor you will have to purchase a CP1320 compressor. Kit includes all necessary parts to rebuild the piston "SLYD" Rings, Square piston seal and cylinder seat seals, as well as all necessary parts to rebuild damaged valves and seals and finally the bearings and shaft seal.