ST stands for "short-travel" - 1.3" of travel is ideal for cross-country racers, road, or comfort riding where you just need to take the edge off bumps without the complexity of a true suspension solution. A patented 4-pivot force aligned parallel linkage keeps the pedal to saddle distance nearly constant through its travel. An aluminum mast and links, rebuildable stainless pivots, and bronze-impregnated PTFE coated steel bushings keep the weight down to 460 grams - barely more than a traditional rigid post. Weight: 454-474 grams, depending on size Feature: 1.3" of travel | Cane Creek ST Thudbuster Seatpost Black, 30.9mm X 353mm