Premium Quality Shaker Bottle: High quality plastic protein shaker bottle BPA free, special designed stainless-steel spiral spring stirrer, very good leak proof lid and flip cap. Designed with a standard protein shaker cup and two screw-on attachments, including a powder container and sectioned pill container, weve made storing proteins, vitamins, and supplements even easier on the go. Efficient Mixing: Stainless steel shaker bottles for protein mixes use a spiral spring stirrer, which can mix the protein shake faster than the stirring ball, so that it will not clump while shaking it will hit the bottom so that there is no more residue on the bottom. Portable non-slip and leak-proof: Our protein mixer bottle is suitable for most car cup holders and bicycle water bottle holders. It is convenient for you to carry around. The cup body has scale marks.