? Made with the top food grade Crystal clear plastic. ? Light weight and fits great on YETI Rambler along with any of the other similarly sized tumblers like RTIC, BOSS, ARTIC, TITAN, MAGNUM Steel and many many more. ?Sliding open and shut closer that is straw friendly, great for on the go. Note The sip hole cover is not designed to create a watertight seal and will not prevent leakage if tipped over or held at an improper angle.