Number BRNY, Permanent pump wear protection. Good used case halves are a challenge to find. New aftermarket are available, for a price. The problem with merely replacing the case is it won’t solve the problem. Magnesium cases are soft; aluminum pumps are harder. The problem will come back. Maybe on someone else’s watch, but surely you pride yourself in fixing problems. Due to the laser-cut accuracy in the manufacturing of the BRNY case protector and the original pocket design, end-play is unchanged. Save yourself money and fix the problem the first time with this simple drop-in.