Our take: The SRC motorized 2500rd drum magazine for R36 metal gearbox AEG rifles is a high quality automatic-winding drum magazine that is designed to maximize the ammunition available at your immediate disposal. While mid-cap mags hold about 100-130 rounds and hi-cap mags hold about 400-500 rounds for the R36 rifle variant, this motorized drum mag holds 2500 rounds of BBs for a virtually endless supply of BBs being fed to your R36 rifle via pressure switch.
The only caveat would be to not fire your rifle on full auto for more than 7-10 seconds at a time, due to the tremendous wear and tear that could build within your gearbox.
This motorized drum mag is compatible with most-all metal gearbox R36 AEG rifles, including R36C, R36K, and R36E variants. It is quality manufactured by SRC and runs on 4 'AAA' batteries (not included).