About A Chair AAC 50 office chair by Hee Welling

HAY describes the AAC 50 as combining "optimal functionality with modern aesthetics," featuring "the same sleek, characteristic shell of the series, on a five-legged castor base in cast aluminium, equipped with a gas lift that adjusts the seat height." The brand presents it as "a versatile and multi-functional office chair," suitable for both the workplace and the home office.

The shell: recycled polypropylene, what HAY calls "2.0"

The seat and backrest form a single injection-moulded shell made from post-consumer plastic waste: this is what the "2.0" in the colour names refers to. The material is dyed throughout: a scratch will not reveal a different colour underneath, and maintenance is limited to soapy water. On lighter shades, slight variations in tone are inherent to the recycled material.

The base: five legs, castors, and gas lift

The base is a five-legged star base in cast aluminium: HAY writes cast aluminium five-legged castor base: mounted on castors. Five legs rather than four: this is the stability standard for rolling chairs, as a four-legged chair tips over too easily when leaning forward.

A gas lift adjusts the seat height. It is a pneumatic cylinder: a pressurized nitrogen cartridge, operated by the lever under the seat, which lifts the chair effortlessly and locks it at the desired height. It requires no maintenance and can be replaced as a spare part if it eventually loses pressure.

Note on height dimensions. HAY publishes a single overall height for these chairs. As the seat is adjustable via gas lift, this value corresponds to a specific position, not a fixed height.