Transparent valve body design fully transparent valve body, observe operation condition to normal use. Double-leaf replica design, upgrade clumsy single page design, two-page open fast, smoke-efficient. Anti-oil sticky, no leakage of smoke silicone gasket, the use of soft washers, strong sealing effect, prevent the smell of smoke. Spring design Check valve with spring, long use, no deformation power lasting, to good sealing performance. Product Name: Pipe check valve Specifications: C: Double-sided smoke pipe Colour: white Material: plastic Package Contents: 1 x Pipe check valve Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.