uxcell Cylinder Shape Fish Tank Bubble Release Air Pump Stone, 1.5cm Diameter Aquarium Air stone; Color : Gray, Black Material : Mineral Stone, Plastic; Inlet Hole Diameter : 2.2mm/0.086" Total Size : 90 x 15mm/3.5" x 0.59" (L*D) Weight : 22g Package Contents : 1 &times; Aquarium Air stone