UL Standards free download UL 1696-2021 pdf download – Mechanical Protection Tubing (MPT) and Fittings UL 1696-2021 pdf download - Mechanical Protection Tubing (MPT) and Fittings. 3.3 Connector – A fitting intended to terminate, secure, and support MPT to an enclosure, equipment or similar device. 3.4 Coupling – A fitting intended to... 02-11 Download Now