I found a holster today that looks promising as a holder for our larger mod units. It's made for flashlights approx. 1" in dia. and its about 5" long. Looks like its made out of some kind of spandex material that will stretch to fit. The holster has a wide pocket clip attached to the back plus it is equipped with a metal hook so a chain or safety hook can be attached to prevent lose. At $3.99 not a bad looker. This holster can be found here:
Nebo Tools Tool Cases | ToolBarn.com
Nebo Tools Tool Cases | ToolBarn.com