Mister Landscaper MLA-50 1/2" Drip Irrigation Poly End Crimper (3 Quantity) Made in the USA To winterize or flush out the 1/2-in poly tubing, slide the crimper forward to release and un-crimp the tubing This fitting works with 1/2-in poly tubing that has an inside dimension of 0.600-in and an outside dimension of 0.700-in