Nautilus Designs Derwent Polyurethane Draughtsman Operator Chair With Spring Loaded Backrest Mechanism Black - DPA/POLY/FCK DDOur durable wipe clean polyurethane operator chair is ideal for numerous applications, offering a spring loaded backrest mechanism, back height adjustment and a robust gas lift for easy seat height adjustment. The chrome foot ring is height adjustable and can be set at any point on the gas lift. Arms may be fitted retrospectively.