Chair with aluminum fixed trestle base on self-braking castors (color matching base). Seat with built-in self-tensioning weight response mechanism, backrest (color matching base) with 3-position recline, adjustable lumbar support breathing up to 60 mm. Medium backrest with front in polyester mesh in the same color as the backshell (black or white). Seat upholstered in leather, customer's leather, coated fabric, fabric or customer's fabric. Fixed or adjustable armrests in nylon fiber, color matching backshell, are available upon request and with a surcharge.