Thomas & Betts LL Series Conduit Body, Aluminum, FM7

Yes. The LL Series bodies are threaded conduit bodies, so they take threaded rigid metal conduit or IMC in the matching trade size, from 1/2 inch through 2 inch. For EMT you would need threaded adapters or a set-screw/compression fitting arrangement, since EMT is not threaded.

Sand cast aluminum. That makes it a match for aluminum rigid conduit and avoids the dissimilar-metal corrosion you can get pairing aluminum raceway with a ferrous body. It is also the lighter choice overhead. Where the run passes through concrete, soil, or an environment with chlorides or strong alkalis, aluminum is generally the wrong material and a malleable iron or PVC-coated body is the better call.

Five trade sizes: 1/2 inch (LL17SA), 3/4 inch (LL27SA), 1 inch (LL37SA), 1-1/2 inch (LL57SA) and 2 inch (LL67SA). Order by the trade size of the conduit you are running, since the hubs are threaded to match that size.

Plan on the cover and gasket as part of the install. A conduit body is not usable until the access opening is closed, and the cover plate (plus a gasket where the location is damp or wet) is sized to the body, so match the cover to the same trade size you order, 1/2 inch through 2 inch on the LL Series.

Only if the body is marked with its cubic inch capacity, and then only within that volume. Conduit bodies like the LL are intended as pull and routing points at a change of direction; splices and taps are permitted in a body only where it is durably marked with its volume and the conductor fill rules are met. For a run that needs a dedicated splice location, use a junction box instead.

Match on the manufacturer part number stamped on the body. The Thomas & Betts aluminum LL Series runs LL17SA at 1/2 inch, LL27SA at 3/4 inch, LL37SA at 1 inch, LL57SA at 1-1/2 inch and LL67SA at 2 inch, all sand cast aluminum. If the existing bodies carry a different suffix, they are a different material or configuration and the covers may not interchange.