uxcell 12-Piece 2-Way Aquarium Air Line Tubing Control Valve, Yellow Aquarium Air Valve; Material : Plastic Color : Yellow; Connector External Diameter : Max 12.2mm/0.48" Thread Diameter : 9.3mm/0.37";Total Size : 45 x 24mm/1.78" x 0.94" (L*W) Weight : 38g 20 x Aquarium Air Valve