Back in november of 2009 i bought a autococker prostock on ebay for $107 shipped. It came with an old halo hopper and a 2 piece empire barrel (16 inch with 687 back). It was horrible timed because it wouldnt cycle properly. I new this from the beginning cause it said so in the seller's ad. I bought it anyways since i enjoy paintballing and tinkering. Well after watching a few vids on youtube, i figured out to time it better. I went paintballing last sunday feb 31,2010 and brought back 2 full tanks of air and decided to finally time the sucker. Took me a good hour since im new to autocockers. I always liked them, but back then they were too expensive. Its pretty much all stock except for the barrel and cp feedneck which will only mate up to the halo loader it came with. The halo hopper seems to have a metal collar on the feed neck that makes it fit perfect on the feedneck. I dont like this hopper cause its old and the motor runs pretty weak(must be 10+ years old). Anyhow next time i go out ill be using this when im playing against lesser players since they usally have rentals,tippmans,mech spyder's.