Stages SB200 Fore-Aft adjustable accessory seatpost give an additonal 10 centimeters to the standard 45mm associated with the seat rail only adjusment on the standard seat post. This brings the total range of SB200 fore-aft travel to over 25cm. Please check your fit prior to purchase as you may not need this accessory to achieve your normal outdoor fit unless your at the edges of the overall size or trying to generate a non-standard geometry (triathlon or time-trial). Adjusment is made via the 8mm wrench that's used for seat height, handle bar height and handle bar reach.