Multi-position adjustable height seat post

A multi-position adjustable height seat post comprising:

• an inner tube,
• an outer tube, movably connected to the inner tube, consists of at least one inner piece and one outer piece, the hardness of the inner piece is higher than 200 Vickers Pyramid Number.
• a locking assembly, comprising an actuating unit connected to the cable, a plurality of parallel grooves located in the outer tube, a plurality of detent elements located in the grooves, and a plurality of spherical elements located in the inner tube between the actuating unit and the outer tube,
• a triggering device, connected to the actuating unit,
• a first extending element, constantly applying a force to push the actuating unit moving in a first direction;
• and
• a second extending element, acting between the inner and outer tubes,
• wherein once the triggering device is triggered, the actuating unit moves in a second direction contrary to the first direction and makes the spherical elements to move inward laterally to let the inner tube and outer tube move relative to each other freely.