This VLTOR receivers at eBaybanned are more expensive than the actual ACM GBB rifles, but for those who want to put some markings to make their GBB rifles look better with all the trades that many of us are crazy about. This is compatible with the WA, AGM, and JG M4 Gas Blowback Rifles, which means you may have to forget putting it on a WE or KJW GBB M4. Costs US$166 and available in Black and Tan colours.