The Freedom Art Mag Pipe for Tokyo Marui airsoft SOPMOD Magazines. Convert regular Marui stype hicap and lowcap mags (Echo 1, JG, G&P mags will also work!) for use with your SOPMOD M4 blowback gun by Tokyo Marui. Instead of buying tons of SOPMOD specific magazines, just buy this conversion piece instead! Fits on the end of your mag, then use it in your SOPMOD. The only downside to using piece is that it won't hold the bolt back when your mag is empty. Other than that, works perfectly!