H2-4 is for hand-cyclists that have moderate to highly affected movement in the trunk and legs or the absence of limbs.
Most riders can use their nearly all of their trunk to generate power and transmit it to the bike with unaffected arms and hands. Some riders will use a kneeling position.
A time factoring system is used where the clock runs slowest for H2’s, faster for H3’s and faster again for H4's.