When it comes to inserting magazines into it, I can immediately provide the dimensions: 6.5 x 8.5 x 13, but please remember that there is a divider separating the two magazines. It stretches to 7-8 cm, which gives us a maximum of 4 cm for the magazine's width. Of course, the pouch can be stretched or squeezed. An M4 magazine fits, the elastics stretch to a maximum of 20 cm. The pouch model is not equipped with fasteners; you just need to slide the straps under the MOLLE webbing. The pouch itself is not bad, it just needs to break in and stretch out. The only downside for me is the method of attaching it to the vest; I simply don't like this type of MOLLE straps on pouches, but everyone has different preferences.