A guy frequently borrows one of my rifles for 3-gun matches and he once returned it with one of these sights on the right accessory rail on a 45 degree mount -- he uses an ACOG for the long targets and the JP for the shorts (unfortunately he remembered to take off the ACOG!). This one below is the one he had.
jpoint.jpg
If that's the one you mean, you should know it's entirely made of plastic, including the lens/screen. Don't know if that's good or bad.