This is the rail that sits on top of your MR2 or MR3 MilSim marker and houses the distinctively designed snap-t bolt cocking mechanism. It doubles as a Weaver style 7/8" Picatinny tactical sight rail as well. Rusted, dusted, crusted or just plain busted, you now have a means of replacing it with the assistance of SPPS.
This is a replacement for Kingman part #269 or VBT011 in your manual.