Most chairs decide in the factory where your lower back should be supported. This one leaves that call to you: the lumbar pad moves to meet the exact curve of your spine, so the same seat can be set up for a short user and a tall one without either of them stuffing a cushion behind their back. Above it, a 2D headrest with a 13-inch by 6-inch pad shifts to catch the base of the skull, and the 21-inch by 19.5-inch backrest rocks from 90 degrees to 115 degrees whenever you want to lean out of a working posture. A tension control sets how firmly that rocking pushes back, and a lifting lever raises the 20-inch square seat through a 17.5-inch to 21.5-inch range, taking the whole chair from 43 inches to 47 inches tall over a 25-inch by 23.5-inch footprint. The back and seat are strung with breathable mesh over high elastic sponge, a pairing that lets air move through the panel during long work sessions instead of trapping heat the way a solid padded back does. Both armrests run 25 inches long, adjust between 25.5 inches and 29.5 inches high, and flip up a full 90 degrees so the chair slides under a desktop and gives back the floor space it was occupying. A premium gas lift, a stable five-claw base measuring 23.5 inches across, and universal wheels that roll on any floor carry a rated load of 350 lbs on a frame that weighs only 24.5 lbs, and assembly is needed before first use.