TriTech Tactical’s TPG-ARG series of grips allows AR based, Glock magazine compatible pistol caliber carbines to carry a spare magazine inside the grip. The TPG-ARG series of grips mount to a standard AR-15 lower receiver grip interface and can store a Glock magazine inside, where it can be released by a button. The grips are available in two sizes – the TPG-ARG915 for full-size magazines and the TPG-ARG910 for sub-compact, compact, and full-size magazines.
TriTech Tactical appears to be working on a second generation of this grip and is soliciting feedback on their website.
not bad, one handed clap…