These are the latest and greatest little hop ups for your Autococker. These are SUPER light and even have a hole on top for vertical Pull Pins if your bolt supports it (most do). Also has a set screw for the pump arm to keep it from sliding around on you!
The MACDev 2K Back Block is older, so while it may be available used and in a few cases new, it is not commonly available anymore.
this back block is awsome, it is super light, and has really cool milling done to it. this block also accepts vertical pull pin which is AMAZING. the vertical pull pin looks so pimp. this back block also looks great with the mac dev sonic pull pin too. the only problem is it is hard to find bolt's that accept vert. pull pins. ( i recomend the AKA lightning bolt).
this back block owns all other backblocks, if you want a good cosmetic upgrade, get this block! i give it a 9 cause the reverse "P" block is the only cooler block out there.