uxcell 5-Piece Cylinder Shape Fish Tank Air Pump Airstone Set, White Aquarium Airstone; Main Color : White Material : Mineral Stone, Plastic; Stone Size : 2.5 x 4cm/1" x 1.6"(D*H) Outlet Hole Out Dia. : 4mm/0.16" Weight : 101g Package Contents : 5 x Aquarium Air stone