PEX GUY Crimp PEX Tools are used with Copper Crimp Rings to secure any standard ASTM PEX tubing to Brass & Copper (ASTM F1807) fittings and PPSU (F2159) fitting systems, also commonly known as barb fittings systems. The economical yet reliable option that has been trusted by experienced Plumbers for decades, the PEX Crimp system is one of the most widely used and widely available fitting system in the market. Comes in 3/8”, ½”, ¾” and 1” sizes. Crimp Ring Removal tool safely cuts the PEX and rings without damaging the fitting so you can reuse the fitting or crimp another PEX connection onto the existing system for a quick repair. Please take note that they are not compatible with PEX AL PEX Tubing, or Expansion type fitting system (UPONOR).