Superior Tool Pex Pocket Crimper. It includes a Go/No Go Gauge, Pex Crimper, and a convenient holding pouch. It crimps standard Pex copper rings using your own 10" vise grips. It fits all common sizes: 3/8", 1/2", and 3/4". It is made of solid hardened alloy steel and requires no adjustments. It meets ASTM F1807 spec for crimping Pex. It has a lifetime guarantee.