Fast ace 11 inch (280mm) BDA51RC/BS58RC Rear Shock with Reservoir 550lb/in Piston Pole: 12mm Distance: 250-350mm Travel: 55-90mm Adjustable rebound swith F (fast) and S (slow) at the bottom of the shock. AL7005 shock body as well as AL6061-T6 upper & lower mount forged. CR-MO piston pole. Steel Alloy Spring, Nitrogen charged, Oil Shock Absorber with external piggy back Reservoir, rebound adjustment 12 clicks and compression 14 clicks.