Elastomer bumpers control both rebound and damping Bumpers adjustable for both rebound and damping 180 day manufacturer Warranty & Service program employed with every set Dramatically reduces vibration due to pivoting and shock absorbing design Reduces arm pump and fatigue by transferring less abuse to the rider. Fasst Flexx bars reduce arm pump by isolating vibrations and impacts, keeping them away from your hands so you can retain much more of your grip strength without suffering from arm pump.