Chair with aluminum swivel trestle base on glides. Seat with built-in self-tensioning weight response mechanism, backrest with 3-position recline, adjustable lumbar support breathing up to 2 3/8". Medium backrest with visible backshell (available in black and white) and front back and seat upholstered in leather, customer's leather, coated fabric, fabric or customer's fabric. Fixed or 2D adjustable armrests in nylon fiber, color matching backshell, are available upon request and with a surcharge. Back and seat can be ordered in different colors of the same upholstery, with a surcharge.