Bite the mouthpiece to serve your drink. Upgrade the mouthpiece to make it easier to get caught. Adjust the flow of your drink by twisting the blue part left and right. Compatible with hose inner diameter (diameter): approx. 0.25 inches (6.35 mm). Compatible with OEM brand products, CAMELBAK, OSPREY. Dust cover included. Hose is not included, picture is for installation Product specifications may change without prior notice depending on the production lot. Simple packaging.