AVAILABLE WHILE SUPPLIES LAST Reuseable, lightweight and risk free! Our most popular size, the 27oz Classic is ideal for busy, on-the-go folks. The 40oz Classic is great for long trips, camping and of course, everyday. Klean's leakproof Loop Cap safeguards your bag or purse, and Sport Cap 3.0 is ideal for the gym, featuring a soft silicone spout, 25% higher flow rate and "chirp" free experience.