Shimano TIAGRA CN 4601 10 Speed Chain Silver pickuponly The Thomson seatpost design incorporates 210000052678 The Thomson seatpost design incorporates a bending fuse to prevent catastrophic failure while load is placed on a connection) Super Narrow Hyperglide (HG) series 10 speed compatible directional chain recommended for Tiagra drivetrainsChain uses a directional design with specifically shaped inner and outer plates to optimise shifting over the chainset and cassetteOuter plate design has been developed to reduce the chance of chain suckThe inner plate has been developed for better contact with gears providing smoother shifting under high load