Item: two ways valve Type: umbrella Material: fluorosilicone/ nbr/ silicone/ fkm Hardness: 55±5 shorea Inner diameter: 4.42mm Outer diameter: 11.74mm Opening pressure: 2-4kpa (duckbill) Opening pressure: 6-10kpa( umbrella) Color: red/black/white/clear Sample: 2 pieces free samples