GoCup expands with a quick pull and collapses to an ultra-compact puck all with a simple press. Lids on both sizes keep things clean during transport and feature handy pill holders. The 8 fl. oz. size also features a clever "DoubleDecker" tray that gives you the option of two small chambers (to organize pills, for example) or one large chamber. The DoubleDecker also creates a handy portable pill box you can take on-the-go by itself. Volume markings on the cups help to measure fluids. All GoCups are PC-free, phthalate-free, and BPA-free. They're perfect in any toiletry kit, backpack, book-bag, briefcase, purse...most anywhere.