I have a Specialized bike with the SWAT mounting holes underneath the saddle, and I just got a PDW (Portland Design Works) "Gravity" taillight, and I'd love to be able to mount it to the seat like your other SWAT mounts for other lights. The PDW mount style actually looks a lot like the mounts for the Moon Nebula and Cateye rear lights, so I wonder if it's compatible with either of those.