The Dual Sizer is a molded adapter that enables you to mount small diameter pipe firmly in place on a run on large diameter duct for concrete encasement. This adapter fits the Vertical-Lok spacers. This is a fast, economical way to position 1", 2", or 2 ½" conduit. The Dual Sizer is manufactured in two nominal sizes, designed for Schedule 40 PVC and will also fit fiberglass rigid EB type PVC and polyethylene pipe.