The YETI Rambler Bottle MagDock Cap incorporates a genius design for the active and on-the-go person. The MagDock bottle cap uses powerful magnets to securely fasten the top to the magnet docking station on the bottom of the lid, insuring you won't lose or misplace it as with other bottle caps. another ingenious design by Yeti! And that's not all. The Rambler MagDock cap also has the perfect size spout which allows you go chug down that H2O as fast as you like with out your ice cubes getting in the way. And of course, Yeti's MagDock Rambler cap is also dishwasher safe and 100% leakproof.