Material: Full metal;Size: 1/8"(9.7mm); 1/4"(12.7mm); 3/8"(16.5mm); 1/2"(20.5mm);Good sealing performance; High compression resistance; Simple installation; It is not easy to fall off; Light weight.Product features: High quality raw materials; Durable and corrosion resistant; Suitable for gas, oil and water.