Specialized Command Dropper Post for sale. $150 OBO. Works completely, 3 predetermined positions. Fits 31.6 mm seat tube. Anyone who has ever ridden with a dropper post understands that there is no going back to a standard seat post. This is a great cost! Due to the fact that it will not fit my new frame, just selling. Going to trade for similar dropper post @ 30.9 mm. e-mail through the link above or call/text @ 435- seven 0 5 - 4 absolutely no 7 9.