Internal Ratchet with Self-Locking feature protects against vibrations. Screw cable glands into NPT Thread (National Pipe Thread). Watertight. ‘Collet' design of body accommodates various size cords, cables, tubing, etc.. Nylon NPT thread cable glands body material is resistant to most common chemicals & solvents. For best results, use the minimum size that fits into your cable. Easy to Assemble. Wide Clamping Range. No disassembly required. Made of UL approved NYLON 66, 94V-2 (Black).