This holster is designed to be concealed by being pressed against your body armor. The backside of the holster has a two inch wide strip of velcro that attaches the holster to the vest. The vest straps can then be placed over the holster adding extra security to it.
This holster can be position in any direction and any location of the vest where there is velcro. The holster is also molded to the firearm for retention, but I don't recommend placing it upside down.