The Tioga D-Spyder 'S-Spec' pivotal is 145g of steady goodness. Start with Tioga's proprietary shell, designed with ergonomic contours for better sitting position. Next, full cutout webbing for additional weight savings, matched with reinforcement ridges underneath for exceptional impact resistance. Then add in the lightweight alloy pivotal hardware, and the result is 5.1oz of reliable seating goodness.