Large opening for easy cleaning and filling - our bladders have one of the largest openings on the market. Large opening for easy pouring. It's also fairly wide, allowing easy access to the water bladder inside by hand or a bottle brush. The 4" (about 10.2 cm) screw cap is easy to open and close. For cold water, just add ice cubes from a spoon and refrigerator dispenser. The smooth interior of the pool promotes health and is easy to clean.HIGH QUALITY - The entire water bladder is made of high quality materials. CHERAINTI water tanks are odorless, SGS certified, 100% food grade. Tested to meet international safety standards. Does not leave bad taste in beverages. The water bladder has passed the pneumatic pressure test and can withstand pressure. Double sealing side technology, the durability is greatly improved. Possibly the most rigid water bladder on the market.KEEP PERFECT HYDRATION - This 2 liter tank can withstand temperatures from -20 to 50 degrees Celsius. The tube is resistant to temperature changes in hot and cold weather. The 14.2"L x 6.8"W (~36.9cm x 17.2cm) hydration bladder is compatible with most hydration bags. The tube (0.37" diameter, 40" long) provides a wholesome flow for easy drinking and keeps you hydrated while biking, hiking or running!Seals well - our high flow bite valve keeps you from slowing down. Just bite the mouthpiece to absorb water. Soft mouthpiece, easy to open/close valve. It also comes with a lid that prevents dirt from getting in. Easy control of water flow through bite. The quick release tube is removable. When the tube is removed, the connector automatically closes and the bladder will remain filled. Store neatly in the fridge/ice box without tangling hoses.