The 9808OS-AB is the 9800 series oversized throne with Quick Lock base and height adjustable back rest. Lined with a Cordura top and vinyl edges this throne top serves as a comfortable and supportive base when sitting through long sets. The double braced heavy duty leg base is fitted with Gibraltar s Super Foot for support and the Quick Lock clamp so that height adjustment is effortless. The GABR back rest is equipped with a height adjust function to fine tune back support.