***NOS RARE*** aftermarket M&W Cylinder Kit (includes 4 sets of pistons, sleeves, rings, pins, and locks for one engine) for C, A, AI, AV, B, BN, Super A, Super AV to ser. 310.300, 130, 140, U2 Power Unit, U-2A Power Unit to ser. 22113. All with crankcase #251069R1. Piston set have M&W "Jet Black" oil impregnated sleeves.