The Sure-Flex PVC Universal Corners can be used on Sure-Flex PVC and KEE HP membranes. Carlisle's labor-saving, pre-molded Sure-Flex PVC Universal Corners are ideal for flashing corners on a variety of details. Its installation is quick and simple with no stretching required. CFAs are the only factory-fabricated PVC accessories that meet the stringent quality tolerances required to be included in a Carlisle warranted roofing system.