This is the holster itself that requires M3 inserts. You will need a belt part that can be found in my Mk4 holster (https://www.thingiverse.com/thing:7045450) that requires m3 screws. There are various types of belt attachment options, large and small, straight and angled depending on taste.

The holster is a snug fit with an open top to ease insertion. It is made for the range, not for CCW or running around (although it would be funny to meet someone who carries an AW93).

A left-handed version is included if you shoot with the correct hand.