Rockshox Reverb Main Piston/Shaft When the dropper stops droppin', it's time for some repairs. These are the internal components for servicing the Reverb and Reverb Stealth mechanism. Features Shaft 355X100mm / 380X125mm Fits A1-A2 generation externally routed Reverb seatposts For "A1" designated posts, 2010-2012 A1 posts have a silver return speed adjuster on the remote and no laser etched logos on stanchion by the saddle cradle For "A2" designated posts, 2013-2016 A2 posts have a black return speed adjuster on the remote and no laser etched logos on stanchion by the saddle cradle Manufacturer Part Number: 11. 6818. 018. 000 UPC: 710845713446 | Rockshox | Reverb Main Piston/shaft 420X100Mm