Consist of resistant Polyethylene terephthalate and reinforced nylons/fiber buckles, smooth drinking surfaces and vibrations proof stability Three size elections adapt to varying workout durations while maintaining leakproof For cyclists, mountain bikers, and outdoor lover needing reliability hands freely hydratation solution during high intensities activity Secure Quickly Release Bike Water Bottles Polyethylene terephthalate component ensures safe hydratation and instants bottles fixation during intense cycling attaches to bike frame or backpacks for trail, commuting, or fitness training with its snap on/off mechanism