Thudbuster LT suspension seat posts provide smooth travel for hard tails, road bikes, tandems, or any other bike with a rigid rear end. FEATURES: Thudbuster Parallel Linkage technology compresses along the opposite path of a bump (down and rearward) to absorb the force, resulting in a natural suspension feel without being overly active, as well as more travel without compromising pedaling position Threaded, serviceable, hard anodized aluminum axles, flanged PTFE bushings