Plastic inserts allow for smooth and quick magazine changes. This is a modular type compatible with the MOLLE system. .45 Single/Double Column, 9mm Single/Double Column, Glock Magazines, SFP9, Hi-Capa, USP, etc. will fit. It is easy to insert the tool knife and light by removing the insert. If you want to change the retention tension, remove the insert and boil it in hot water or warm it with an industrial dryer and deform it. The fastening part usually uses 3 rows and 6 frames. It is not impossible even with 4 frames if you push it in from both sides. Although it has been opened after purchase, it has not been used even once, so there are no scratches or dirt. Thank you for your consideration.