It has mixed my whey powder and milk fantastically no lumps!

It worked great for a while, the built-in mixing blades on the inside worked great to shake mix without the need for a rattling mixer inside. Unfortunately, after a few weeks the aluminium ring around the plastic lid came away, as it's just glued in place, if this was the only issue, it would have been fine. The glue on the plastic was unsightly, but it still worked. Then as many others have reported, the cap tore at the lid. For the repeated use of being stoppered and unstoppered the plastic is too thin and it eventually just tore away with the cap still inside the top.

It looks really cool I like it but after using it twice top lid just ripped off I am not really happy about the quality of the plastic on this product.

Great shaker use every day. Easy to clean, does exactly as what it says in the products description 

top plastic part is very difficult to clean. opening tab broke off, on two shakers. not a good design