Quality seal: caps with seal and stainless steel Convenient: Swing- offers a simple, reliable capping solution. Cost-effective: Reusable, for repeated use. DOES NOT WARP OR LEAK CHEMICALS - Ceramic maintains its shape and will not leak chemicals like plastic, which could affect the taste and quality of stored liquids. FULL GASKET SEAL FOR BETTER CARBONATION - Other caps use a circular gasket with a hole in the middle, seal features a full silicone gasket to provide maximum seal. Scope of application: Suitable for beer, soda bottles, home brew, and other liquids. Colour:As Shown Material:Stainless steel,Silica gel Package Contents: 4x Sealing cover Only the above package content, other products are not included. Note: Light reflection 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. FULL GASKET SEAL FOR BETTER CARBONATION - Other caps use a circular gasket with a hole in the middle, seal features a full silicone gasket to provide maximum seal. Cost-effective: Reusable, for repeated use. DOES NOT WARP OR LEAK CHEMICALS - Ceramic maintains its shape and will not leak chemicals like plastic, which could affect the taste and quality of stored liquids. Quality seal: caps with seal and stainless steel Convenient: Swing- offers a simple, reliable capping solution.