【Leak Proof】Except for the silicone stopper inside, there are 4 stainless steel balls inside which can grip the bottleneck firmly preventing your wine from spills or leakage. You can lay the bottle down or keep it upright for storage. 【Rotating Lock Design】 - More efficient and easier to use, only needs to rotate the upper part of the cork to unlock, and then plug it into the bottle mouth tightly, and then turn the wine cork. The upper part is locked back to the original position to achieve sealing save. 【Efficient Sealed Storage】 - By optimizing the internal structure, a sealer makes the wine stopper fit perfectly and tightly locks the gas in the bottle to prevent the bubbles from slowly dissipating after the wine bottle is opened. 【High-quality Materials】The internal sealing parts of the wine stopper are selected for use with food contact grade silicone materials, and they are more secure. Wine stopper shell is made of durable ABS material, which is not easy to wear and easy to clean. 【Wide Applications】The wine stopper's inner diameter is 18.5±0.5mm, they are suitable for standard wine, grape wine,beer, and soda bottles(Champagne bottles are not applicable), and are also very suitable for various occasions, such as homes, parties, hotels, clubs, bars, etc. If the wine bottle cap doesn't fit your bottle, please contact us, we will reply and solve the problem within 24 hours.