There are a total of 4 aquarium gas regulating valves in 2 styles, so please check the sizes.
Specifications:
Type: air flow control valve
Material: stainless steel
Color: silver
One size: inlet diameter: 0.16"/4mm; outlet diameter: 0.16"/4mm, 2.17inch/55mm*2.36inch/60mm
Another size: outlet diameter: 0.16"/4mm; inlet diameter: 0.31"/8mm, 1.57inch/40mm*2.36inch/60mm
Packing List:
55mm Air Flow Control Valve*2
40mm Air Flow Control Valve*2