Set of 2 wine stoppers provide an air-tight seal to preserve opened bottles of wine. Suitable for all regular red and white wine bottles. Turn the top anti-clockwise to loosen, clockwise to tighten. Twist to seal is a more effective way than the lever one and the silicone you may need to push inward hard to avoid leaking. Almost no effort to lock and remove it from the bottle. There are 4 steel balls inside which will grip the bottle neck. When installed well, you can even lift the bottle and it will not fall off. No leak if you lay the bottle down in the fridge.