At AquaCave, we offer some of the best selection & best prices on LocLine fittings and accessories for you marine, reef, and freshwater aquarium. Loc-Line system from AquaCave offers excellent combinations of fittings and sizes for fantastic results. There are a variety of sockets, fittings, reducers, valves, nozzles, and adapters. Loc-Line is available in 1/2" or 3/4"ID.