Excellent Material:Made of Hot Forging, Perfect and Meticulous Polishing. Hardened Steel Construction Ensures Reliability and Durability. Built-in Dual Jaw:The PEX Crimping Tool with Built-in 1/2 & 3/4'' Well-polished Jaw and Smooth Actuation Mechanism Allows Secure Connection with Minimal Force Required. Compatible:Works with 1/2" and 3/4" Copper Ring in Pex Pipe Connection, Meet ASTM F1807 Standard. Application:GUOFIS PEX Crimp Tool is Designed to Compress Copper Crimp Rings to Secure PEX or PE-RT Tubing to Brass or Poly Crimping Fittings. Package Include:1PCS PEX Crimping Tool, Come with Go /No Go Gauge and Free Metal Structure Pex Pipe Cutter.