WE M4-CQB Open Bolt System Conversion

Short inner barrel version for WE M4-CQB
Converts your WE M4 closed system to open chamber system.
Open bolt M4 mags are required to be used with this kit.
One set of mag conversion kit is included
M4/SCAR Open Bolt Mag Conversion Kits

NOTE: this version has the "tabbed" hop-up unit, which secures snugly into the upper receiver, and is beneficial for proper mag seating.