SharkBite 1/2" & 3/4" Pex Crimp Tool. It is for use with 1/2" & 3/4" Pex copper crimp rings. This tool evenly compresses the copper crimp ring, forcing the Pex pipe between the ribs of the fitting to create a secure, leak-proof joint. The included crimping gauge and go/no-go gauge help ensure a quality installation.