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: 1.842, B: 1.898, C:.75, D: 2.11, NPT TS IN: 1-1/2.