Tactical MOLLE and Standard Duty DBL/SNGL Mag Holsters can be added vertically or horizontally. (Set screws suggested if you experience strap slippage when not wearing)
Uncle Mike's has made quality real world use gear for years.
Pros: Mag holsters can be added vertically or horizontally. Ease of adjustment and fitting. (When wearing no slippage.)
Cons: Weapon and ammo weight may require re-adjustment when not wearing due to slippage. Fit too snug for use with rail type lasersight attached.
This review was written in the old system and had content requirements that are different than reviews written today.