uxcell Aquarium Fish Tank Air Line Tubing Volume Control Valve Black 5 Pcs Product Name : Aquarium Air Valve;Material : Plastic Color : Black;Fit Tube Inner Diameter : Max: .5.5 mm / 0.21" Thread Diameter : 0.9cm / 0.35";Total Size : 4.1 x 2.5cm / 1.6" x 0.98" (L*W) Weight : 9g Package Content : 5 x Aquarium Air Valve