Dual Arm Tension:

Belt tension and bale density are controlled hydraulically.  The top tension arm maintains pressure on the belts to eliminate slippage while the pressure on the lower arm develops a more uniform and dense bale.  The belts remain tight, preventing the belts from moving off-track when the tailgate is opened and closed.  Keeping belt tension during the bale ejection helps force the bale out of the chamber and helps prolong belt life.