Lixit Dog Water Bottle, 64-Ounce One piece tube/cap assembly with stainless steel double ball point tube Easy to install; Cleans easily Engineered for superior performance Filling Instructions: Water bottles work on a vacuum lock. When bottle is filled and first inverted, press the control ball and let water trickle out until vacuum develops before placing bottle in holder. True dog water bottles are designed to drip occasionally so the dog can smell the water at the spout. Kindly refrain from to tightening the top too tight. This might damage the product.