OutdoorMaster Hydration Bladder TPU Imported The main part of the hydration pack is made from 0.4mm TPU material with no smells and scratch-resistant surface The mouth of the pack, 90mm in caliber, facilitates cleaning The highly qualified bite valve is equipped with a dust plug The locking structure of the connector can effectively prevent the water from leaking The hose cover is thickened and of insulation to certain extent