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 * 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.