Via Danger Room:

…the Avenger is capable of staying in the air for up to 20 hours, and operating at up to 50,000 feet. Powered by a 4,800-lb. thrust Pratt & Whitney PW545B jet engine, it can fly at over 400 knots — 50 percent faster than the turboprop-powered Reaper unmanned plane, and more than three times as quick as the Predator.