If your reservoir features a Shape-Shift baffle you have the option to leave it locked or unlocked. To lock, reverse the reservoir to expose the top of the baffle. Press the top part of the baffle together and snap the two sides into place. Next, return the reservoir to its natural orientation and slide your fingers down the length of the baffle (on the outside of the reservoir) to engage. To unlock, empty the reservoir, fold the top down and pull the baffle sides apart. Watch this video to learn how. For optimal performance, periodically apply a food-grade silicone lubricant to the baffle.