Fitment: Fits for Annovi Reverberi RK, RKA, RKV, XRCA, XRV, XRCV series pressure washer pumps (also known as AR pumps.) High Quality: Made of high-quality ceramic, steel and plastic. Hight precision and Extra-thick ceramic pistons. This kit is very sturdy and durable that can provide a ultimate performance on pump and can serve for a long time. Directly Replacement: Directly replaces manufacturers part AR2546. This AR piston repair kit contains all that you need to repair broken pistons, O-rings, washers, nuts, plungers. If you have water leaking from the bottom of your pump between the head and the crankcase check to see if your ceramics are cracked. .