There's Slap It , which exfoliates, Bite It , which plumps with collagen, Shake It , which firms and illuminates the butt skin, and Squeeze It , which also hydrates and evens skin tone. At the Chromat show, the models were offered a choice between Shake It, Slap It, and Bite It, with Wiesenberg herself applying the masks. It involved squatting down and lifting the models' bikini bottoms to carefully place the masks — there's two in each package, so one per cheek — on their backsides. The models kept the butt masks on for about 10 minutes just before heading out to the runway.