Thomas & Betts LTZUS01B-C LFMC HLFR UL 3/8IN BLK 30M/100FT

It's 3/8 inch trade size liquid tight flexible metallic conduit, supplied as a 100 foot (30 m) coil. One coil covers a lot of short whips, so most electricians buying it for motor, rooftop unit, or disconnect connections order a single roll rather than cut lengths.

Metal core. The LTZUS01B-C is built on a galvanized steel core with a black jacket over it, which is what separates LFMC from nonmetallic liquidtight (LFNC). The steel core is what gives it crush resistance and, with the right connectors, a metallic raceway path.

That's exactly what liquidtight flexible metal conduit is for. The jacket over the steel core keeps water, oil and dust out of the raceway, which is why it's the standard choice for rooftop HVAC whips, pump and compressor connections, and outdoor disconnects. The seal is only as good as the fittings, so use liquidtight connectors at both ends, not standard flex connectors.

Order it as Thomas & Betts LTZUS01B-C. That number covers the 3/8 inch black LFMC in the 100 foot / 30 m coil, so it's the number to quote for a standardized spec across a facility or a repeat MRO order.

Pick LFMC like the LTZUS01B-C when you want the mechanical protection of a galvanized steel core, for example where the whip can get stepped on, hit by a cart, or exposed on a roof curb. Nonmetallic liquidtight is lighter and easier to route but gives up that steel armor. Either way you run an equipment grounding conductor sized for the circuit rather than relying on the flexible raceway.