Tired of always inflating my 20-ounce shakers, I doubled them. Tested with 50-50 casein and protein isolate, it is smooth without any lumps or solidified casein bubbles. It will be very useful for most people’s long-term physical exercises. I am going to play in the gym for 2 to 3 hours a day, throwing ice cubes on this thing. It feels firm, check for leaks when shaking (fill up to the top and shake violently, turn the blender bottles upside down). No leaks, everything is normal.
The size of the voltrx protein shaker is good. The hook that you carry with you is fragile, and the top cannot be rotated freely, but can only be rotated halfway. It’s ok. Although, I do believe that if the hook and the drinking cap are separated, the design of this blender bottles will definitely be improved.