This hard plastic return jet allows for easily routed water from 3/4″ ID tubing attached to your filtration system back into your aquarium. It may fit aquariums with a frame up to 1.5″ wide. Eshopps’ Return Jet is ideally for freshwater or marine setups. Measures 3/4 x 3.25″ x 5.75″ overall; return nozzle measures 1.75″ x 1-7/8″ x 5/8″ thick with a 1″ diameter swivel ball joint.