At 3 1/8" wide, it is the smallest mag pouch I have come across.
When they form the outer Kydex, they use a dummy round so a full mag will seat and retain properly. The quality is excellent and will last for a long time.
The only down side I found is the belt loops. The Kydex loops ride slightly higher than the back of the pouch, which for me causes a little discomfort if I'm not wearing an undershirt. I would like to see them lower the loop flush or just below the top of the pouch.