Although the AAC 15 version of the About A Chair shares the same distinctive and uncluttered shell, the elegant aluminium four-star castor base casts a more functional slant that makes it perfect for more formal, corporate settings and work-athome offices.‎ The polypropylene shell is available in a large number of colour and upholstery options and the base comes in various finishes.‎Injection moulded polypropylene shell without armrest full upholstery.‎ Shell thickness: 10 mm polypropyplene with 10 mm foam.‎ 4 star swivel base in cast aluminium with wheels.‎ Available in a large selection of standard fabrics and leathers.‎ Available in 3 different base finishes:- Black powder coated aluminium (RAL 9005) - White powder coated aluminium (RAL 9003)- Polished aluminium