Compatibility: The Medium Bottle Boot ONLY fits the Simple Modern 32oz Summit, 40oz Summit, and 34oz Mesa water bottles. The medium size does NOT fit any other size Summit bottle, Mesa bottle, or any other Simple Modern Collection. Maximum Protection: The silicone boot helps prevent dents, scratches and other imperfections on the bottom of your bottle. Customize Your Bottle: The Simple Modern Boot is the perfect way to accessorize your bottle! The Simple Modern Medium Boot is only guaranteed to fit on Simple Modern products Limited Lifetime Warranty & Pat/Pat Pend