Review on Wine Preserver Vacuum Pump Set with 6 Bottle Stoppers & 6 Pouring Discs by DeVine – Robust Stainless Steel & Plastic Build – Air-tight, Leak-Proof Sealing – User-Friendly - Stylish Gift Packaging by Allison Smith

This wine stopper works almost as well on metal screw top wine bottles as it does on bottles with corks. However, a metal screw-top bottle - if anything is slightly larger in diameter (I only had one to try with this pump.) - will only seal, as will those that are initially corked, if the side of the cork isn't lightly pressed exposed, which then breaks the vacuum seal. My strong suggestion is that the company make and then offer a slightly larger diameter cork to eliminate this problem. The company will then sell its wine preserver with both types of closures.