Designed to cap NPT fittings, the EZC series caps can also be used to protect a variety of items. It is a heavy-duty, tapered, multi-use cap with a flange for easy insertion and removal. NPT Tapered Design Flange for easy installation and removal Material: LDPE Standard Color: Orange : : A:.585, B:.662, C:.62, D:.89, NPT TS IN: 3/8.