This is a flip-up sports bottle cap designed to be used by replacing the cap of a plastic bottle. It's recommended as an item that helps you hydrate easily and efficiently without the risk of losing the cap. As shown in the first photo, it comes in five colors: white, red, blue, green, and yellow. You can choose your favorite combination of two, which will be sold as a set (However, we may not be able to accommodate your request depending on stock availability, so please check the combination availability via message before purchasing. If you do not confirm, the seller will choose the combination). ★Important Notes★ ・All items are unused. Please detach the closure of the opening before use. We recommend washing it with dish soap before use as a precaution. ・This product is basically installed after removing the ring (part of the cap) that remains on the plastic bottle body when the original cap is opened, as shown in photos 2-4. If you do not remove it, it may interfere with the installation and prevent you from tightening the screw, which may cause leakage. In that case, remove the ring on the bottom side of the product as shown in photo 5 (you can pry it off with pliers, etc.). ・This product fits the standard plastic bottle mouth size (diameter: approx. 28mm). Please note that it cannot be attached to bottles with different diameters, or even if the diameter is correct, bottles with incompatible threads (although the seller has never encountered this). We do not accept returns for any reason from a hygiene perspective. Please understand and purchase accordingly. #WaterBottle #WaterBottle #Nalgene #Nalgene #Flask #Hydration #Mountaineering #Hiking #Walking #Cycling #StrollGoods #Pet #HeatstrokePrevention #Ultralight #UL #SmartWater #LIFEWTR #SmartWater #LIFEWTR