Compact, rotating deflector turns your existing powerhead into a wavemaker. Simply attach to a powerhead to generate beneficial water movement. Geared unit rotates 360 to produce a wave-like effect without added energy costs - it's powered by water pressure. Improves gas exchange/oxygenation and simulates natural ocean conditions in reef aquariums with corals and invertebrates. Recommended flow rate between 80 to 310 gph. Included adapters fit most outlets. 2-1/4" dia x 3".