The end cap does more than close off the end of the tubing—it also uncaps to provide an easy access point to flush the drip system for maintenance or expand the system as needed. The Smart Loc™ Multidiameter End Cap fits 16mm, 17mm, and 18mm supply tubing and dripline sizes, so there’s no need to fumble around to find the right size cap to close the end of the hose. Reusable fitting is made of ABS plastic treated with UV inhibitors to prevent fading and cracking.