Plumbing fittings, namely, adapters, bushings, caps, couplings, elbows, valves, pipe clamps, tees, reducers and couplers; flexible pipes being parts of basin plumbing installations; flexible pipes being parts of bath plumbing installations; flexible pipes being parts of shower plumbing installations; heating panels used for indoor heating purposes; heating/cooling systems composed primarily of tubes, pipes, and pre-assembled manifolds through which cold or low temperature circulates; heating ...