The BlackHawk T-Series Jacket Slot Leg Strap Adapter is designed to work with the Blackhawk Holsters using the 3 hole mounting platform. It might work with an Alien Gear Holster but fitment cannot be guaranteed.
The BlackHawk T-Series Jacket Slot Leg Strap Adapter uses the screws and bushing on the compatible holster.
The BlackHawk T-Series Jacket Slot Leg Strap Adapter is compatible with the T-Series Jacket Slot Belt Loop adapter and can be used with the Tactical Holster Spacer Kit.
The BlackHawk T-Series Jacket Slot Leg Strap Adapter will work with the Omnivore as long as you are using a compatible 3 screw Blackhawk mounting system like the BlackHawk T-Series Jacket Slot Belt Loop, found by using the link below:
https://www.opticsplanet.com/blackhawk-t-series-jacket-slot-belt-loop-holster-clam.html
The BlackHawk T-series Jsbl Leg Strap Adapters will not work with the Serpa Series Holsters. Those holsters are compatible with the STRIKE line of mounting platforms.