When I asked about this TopTech, general consensus was that it wasn't worth the money at the time (around $600 before shipping) though at $400 from CapitalAS seems to be a sweeter deal. If I remember correctly (so someone correct me if I'm wrong please) at what I was told, internally is pretty much all proprietary. I don't remember if anyone mentioned about it using standard M4/M16 mags though.
"Hey I'm the first one to say its a great country but its a straaaaange culture. This is a place where gun store owners are given a list of stolen credit cards but not a list of CRIMINALS and MANIACS. And now they're thinking of banning toy guns...AND THEY'RE GONNA KEEP THE F**KING REAL ONES!"
-George Carlin 1937 - 2008 (RIP buddy)