Description All of our poly seal screw caps are made using a strong, durable plastic. Insert the cone into the sealing area to create a air-tight seal to prevent liquid leakage, prevent carbonation, and prevent gas leakage when the is tightened, makes a good seal. Features - Color:Black.- Material:Plastic.- Size:3.80X3.80X1.20 cm/1.49X1.49X0.47 inch.- These black lids are made from premium material, to provide good torque retention, reusable and durable, the poly will not rust over time.- Please make sure that the diameter of the bottle mouth is 38mm before purchase, otherwise it will not be applied.- Insert the cone into the sealing area to create a tight closure to prevent liquid leakage, prevent carbonation, and prevent gas leakage, to provide you with a good closure and air-tight seal.- The black seal screw has a raised ridge across the entire circumference, making it easier to hold and seal.- 38mm poly screw can be provided to the variety industries to produce a good sealing effect, and also can fit well as replacement caps for your 38 mm wide glass growler bottles ans so on.Packing list: 5 x Poly Cone Caps