Amazon is notorious for knock-offs, and knock-offs of knock-offs. And amazon warehouses make it worse by pooling inventories of multiple vendors selling the same item. Multiple vendors will send their stock of the same item to amazon to store, and amazon puts them all in the same "bin". When one of those items is sold on the amazon site, a worker just pulls one from the common bin, and the sale gets credited to whichever vendor the buyer had selected. It's very easy for someone to register as a vendor on amazon, ship them a bunch of flimsy grab bars that get thrown in with the rest, and double their own profit while others will get faulted for the poor quality.