Hydro shaker is a shaker & a tumbler cup all in one like a two & one cup one is a shaker one is a tumbler 2 lid combo. Functions as a shaker cup & a tumbler cup . Mix supplements & additives when you insert the shaker grate & pro lid, or use the tumbler lid & sip your favorite drinks through the included straw (this is not glass) made out of some type of very hard plastic