Made of durable silicone, these Dispense All brand blunt needle covers are perfect for sealing off blunt needle ends. Simply slide the cover over the blunt needle to make a liquid tight seal. These are made specifically for 18 and 20 gauge blunt needles 0.5 inches and longer. Please note that silicone is gas permeable so while it will seal a blunt needle, it will let air in overtime. Contains 50 blunt needle covers.