Broken after two weeks.
Shoddy plastic internals mean it is destined to break, the winding spring assembly (turned by the electric winding motor) broke because poor-quality plastic was used to hold both sides of the winding spring.
Enough force and it breaks. Every time.
broken by design.
This mag fit perfectly into my CYMA AKM, but the sides of it were slightly to wide to fit into my CYMA RPK. I used a dremel tool to shave down the sides of it, and re coated the area I shaved down with a Black mat spray primer.
It now works great in my RPK witch was the gun I bought it for. One of the best AK drum mags I've used. I hope to get another one in the new year.