Key facts

AC 4
AC 4
Vitra >
Antonio Citterio >
Order number:
421 942 00 01
Architonic ID:
Manufacturer groups :
Office chairs-Task chairs >
Office chairs-Management chairs >
Office chairs-Task chairs >
Office chairs-Management chairs >

Product description

Precisely refined to suit the requirements of AC 4, the FlowMotion mechanism facilitates a dynamic range of movement and provides weight-adapted support in every sitting position – even when the seat is tilted forward. And thanks to the inclusion of distinct comfort zones in its quilted structure, the backrest provides optimal support for each section of the human spine:

1. Lumbar zone: integrated in the backrest, the lumbar zone provides comfortable and effective support for the lower back. The optional height-adjustable lumbar pad transitions smoothly into the flexible middle zone.
2. Sink-in zone: this flexible zone reduces back tension, removes pressure from the spinal discs and straightens the shoulders and head.
3. Shoulder zone: the support in the shoulder zone relaxes the neck muscles and enables the sitter to effortlessly maintain a horizontal viewing angle for computer work.

The multifunctional 3D armrests have 360 degree swivel movement, which is very useful for desk work.

The timeless appearance of AC 4 is just one aspect of its ecologically sustainable design. It bears the ‚Blue Angel‘ seal for low-emission upholstered furniture and GREENGUARD certification for indoor air quality.

Office swivel chair with 3D armrests according to EN 1335, Ergonomic Seal of Approval.
Mechanical unit: FlowMotion mechanism with synchronised forward tilt (can be disengaged) and with seat depth adjustment. Mechanical unit powder-coated in basic dark.
Backrest and seat: self-supporting backrest structure with horizontally stitched padding. Backrest mount in polished die-cast alumini- um. Optional height-adjustable lumbar support pad. Seat cushion in polyurethane foam. Cover in Plano or Twill fabric or in leather.
Armrests: optionally with fixed, polished die-cast aluminium ring armrests for conference areas (optional leather covers matched to the leather upholstery; for chairs with fabric covers, the leather armrest covers are in the colour nero) or with 3D armrests with polyurethane pads in basic dark.
Base: five-star polyamide base in basic dark or polished die-cast aluminium base with double castors (Ø 60 mm) in basic dark.

635-925 x 530-780 x 1010-1130 mm

Product family


The aim behind the structural design of AC 4 was to discreetly integrate the functional elements required for optimal comfort. Up until now, the design of office chairs has emphasised either their aesthetic appearance or their functional features. By contrast, the integration of ergonomic features in AC 4 is so subtle that its sophisticated structural compo- nents remain concealed. It achieves a balance between the most advanced ergonomic functions and an unobtrusive appearance: the innovative technical features of AC 4 are neither put on display, nor are they hidden beneath foam padding. AC 4 is an emblematic object with an elegant appearance and uncompromising functionality, ideally suited for refined offices and conference spaces.

AC 4 is available as an office swivel chair and in the version AC 4 Conference for meeting venues.