Product Description Size: The stopper is about 3.8cm Material: Silicone Package Content: 6 * 1 stopper.[economical and practical]: A set of 6 black thermos caps. A pump draws air out of the wine bottle and a rubber stopper seals the bottle. 2.[ Stores wine for up to 10 days]Designed for use with all Wine Saver pumps. The pump and stopper work together to remove air from your wine bottle, keeping your wine tasting fresh for up to 10 days. 3.[time scale record]: The vacuum wine bottle stopper records the date the bottle was last opened by simply turning the stopper ring. Four.[ user friendly]: Insert the stopper into the neck of the bottle and pump to release the air until you feel resistance. The less liquid in the bottle, the more you have to pump. Squeeze the tip to expel air before removing the stopper. Five.[valid]Suitable for all red and white wines. Universally suitable for all wine bottles.