quality construction and materials
double stacks the BBs
great price for 2
Will hold 50-60 BBs easily
at ~50 BBs in it gets harder to load
at ~75 gets almost impossible to load any more BBs
Dont actually hold 100 rounds (they could but you would break your speed loader)
DO NOT fit in ICS brand SIGs (at least my ICS 551, got them to fit after a little work to the mag itself, there a little loose, but not much)
I did count the amount of BBs I was using, so the above numbers are not a guess.
Overall, I definitely think there worth getting if you don't like windup mags or the sound of shaking BBs.
Rating: [4 of 5 Stars!]