For this POTD, here is a photo of a holstered Serbu Shorty. Although I don’t think this qualifies as a holster. More like a weapon catch since the trigger and trigger guard are not covered. Unfortunately the image is low res so I cannot make out exactly what is going on with the kedex weapon catch mechanism and how it holds the Serbu Shorty in place. I would hazard a guess that it snaps onto the barrel.