Product Size: stopper is about 3.8cm Material: silicone Package includes: 6*stoppers 1. ECONOMIC AND PRACTICAL: Set of 6 black vacuum bottle stoppers. The pump removes air from the bottle of wine and the rubber stopper seals the bottle. 2. KEEP WINE FRESH: Designed to be used with all Wine Saver pumps. The pump and stoppers work together to remove air from your wine bottle to help preserve freshness. 3. DATE TRACKING FEATURE: The vacuum wine bottle stopper allows you to record the date you opened the bottle by turning the ring on the stopper. 4. EASY TO USE: Insert the stopper into the bottle neck and pump to remove air until resistance is felt. The less liquid in the bottle, the more pumping may be required. Pinch the tip to release air before removing the stopper. 5. UNIVERSAL FIT: Suitable for all red and white wines. Fits most standard wine bottles.