Thomas & Betts LTZES03B-C LFMC HLFR 3/4IN BLK 30M/100FT

It's 3/4 inch trade size liquid tight flexible metallic conduit, supplied as a 100 foot (30 m) coil in black. One coil covers a 100 foot run, so size your order by total footage of the runs plus slack at each termination.

Yes, the LTZES03B-C is built on a galvanized steel core with a black jacket over it. That makes it metallic flexible conduit rather than the nonmetallic type, so it is the product to order when the spec calls for LFMC and not LFNC.

Use LFMC like the 3/4 inch LTZES03B-C where the run has to flex or seal: the final whip to a rooftop condensing unit, a pump or motor that vibrates, a disconnect on equipment that gets pulled for service, or any short length exposed to wet conditions. Rigid and EMT are the right call for long straight runs and structural support, since they don't move and they hold a line. Many jobs use both: hard pipe to a junction near the equipment, then a short length of liquid tight to the machine.

It's a common choice for that. The flexible galvanized steel core takes the vibration a motor or compressor puts into the connection, and the liquid tight jacket handles a wet or outdoor location at the equipment. Cut what you need off the 100 foot coil, terminate both ends with 3/4 inch liquid tight connectors, and keep the flexible section long enough that the equipment can be moved for service without stressing the terminations.

The jacket on the LTZES03B-C is black, which is what most exposed exterior and mechanical room work uses, so it will match existing black liquid tight already on your equipment whips. If any of your buildings were run in gray, the runs will look mismatched side by side even though the conduit does the same job. For a fleet of properties, pick one color and keep buying it.