Compresses stainless steel clamp rings to secure PEX or PE-RT tubing to brass or poly crimp fittings. The three handle design version allows for one handed gripping keeping the other hand free to hold a flashlight, ladder or pipe. One tool works with all size clamps from 3/8 to 1 in. When properly calibrated, this tool eliminates the need to check each fitting ring with a go or no-go gauge.