8.2 meter-miles
In any question which includes "the largest", the answer must include the phrase "so far". As of May 2010, the largest optical telescope SO FAR is the "Gran Telescopio Canarias", or "Great Canary...
The Hubble Space Telescope has a number of instruments, but the primary one is an optical telescope.
reflectors
I think it is the Hubble Space Camera. I'm not completely positive... but I'm pretty sure :)