Hi,
Autobrakes (with antiskid) on the normal only brake system provides auto-braking at selectable deceleration rates for landing and max braking for rejected takeoff.
Autobrake 1
..4 FPS deceleration
Autobrake 2
..5 FPS deceleration
Autobrake 3
..6 FPS deceleration
Autobrake 4
..7 FPS deceleration
Autobrake MAX
..11 FPS deceleration
Autobrake RTO
...Maximum possible deceleration
If RTO is selected for takeoff the system activates on the takeoff roll at speeds above 85 knots when both throttles are retarded to idle.
After landing, autobraking begins at wheel spinup and throttles at idle. Five levels of deceleration can be selected for autobraking on landing: I - 4 and MAX. If MAX is selected, deceleration level 4 is applied until the pitch angle is less than one degree.
As extracted from an unofficial manual.
Cheers