(STR912) These corks are 15/16 inches in diameter and 1-1/2 inches long and are chamfered on both ends for easier insertion. These cork will give a good tight fit with a standard fifth size wine bottle that has a cork finish or has a 3/4 inch opening. This is the size we recommend when using our Gilda Compression Corker, Bench Model Corker, Floor Model Corker or any corker that utilizes as compressing iris mechanism.