Looks like the same thing as the power runner PR2310. I've got one, and it is a nice battery. I've used it only 4-5 times, but have used it with both the JB3 and the Microtrack -- worked great in both cases. Batteryspace.com has them for a bit cheaper than the link Nick posted, $88 I think.
If anyone is interested, I'm probably going to sell mine in the yardsale since I've been using my Segue Juice Box along with a walmart battery for my MT. Drop me a line or look in the yardsale (once I get my act together a get a for sale post over there).