I bought one of the DaYi backs a few years or so ago. When I was looking in to roll film backs I heard reports of a well constructed, all metal back made by them, and a lower quality one with cheap plastic parts. Managed to get an all metal one second hand and it has been fantastic, the build quality is great and it operates exactly as it should. When comparing the prices to others on the market, it was an easy decision for me to make.