It's a Leland regulator I got from Rex Grigg. Very similar to the ADA nano regulator. See this thread:
http://www.plantedtank.net/forums/eq...o2-setups.html
I got a pin-actuating adapter for a 20oz tank. The other end has female 1/8 NPT threads. So I just need a coupler that fits the threads of the regulator (which I'm not sure of). On a related note: anyone know the size of the threads of the 88g paintball cartridges?