"This magazine came with my JG G3, and I must say it is of very high quality. The mag is full metal and the wind-up gear is easy to use. I honestly don't think it holds 500 bb's, but I can't complain because you literally only have to wind it about twice before unloading the whole mag. My gun never skips a shot with this magazine, even with a 9.6v battery! No doubt I will be buying spares of these mags in the future."