The round SHS Sector Chip / Delayer pulls the tappet plate back at the normal time but holds it back slightly longer than a sector gear alone.  If your AEG is not feeding properly because BBs are not getting a chance to be fed into the hopup, this may solve your problem.  This occurs most often on guns with high rates of fire.

If you reverse the direction of this sector chip, it will pull the tappet plate back slightly earlier in the cycle but release it at the normal timing.