Yaoyar Fitness Sports Shaker Bottle, 500ml Small Protein Shaker Bottle with Mixing Ball, Portable Shakes Cup for Workout,BPA free, 100% Leak Proof

These are sturdy great bottles. The shaker thing that goes in them is made of the same material as the cup though and one of ours melted at the bottom of our dishwasher when it accidentally fell. The also don't work as well at mixing the protein powder into the liquid because its not open. The solid plastic ribs. I like the ones that are like whisks better.