Office chair Topstar SI59UG20 — ergonomic adjustable height, swivel seat, caster base

Topstar SI59UG20 is an ergonomic office chair with an orthopaedic seat (Sitness 25, 40 mm / 10"), black fabric cover made of 100% polyolefin, adjustable seat height and integrated lumbar support. The chair includes U2-type armrests, a steel five-star base with casters and a permanent contact mechanism that supports upright posture. Dimensions (W x D x H): 480 x 440 x 420–550 mm, backrest height: 580 mm; maximum load capacity: 110 kg.

Advantages

The chair combines an ergonomic orthositz seat with height adjustment and lumbar support to improve sitting posture during prolonged desk work. The permanent contact mechanism keeps the backrest engaged with the sitter for continuous support while the steel base and casters provide stable mobility. Fabric cover of polyolefin is durable and easy to maintain.

Suitable for

• Home office and study desks
• Standard office workplaces
• Rooms requiring a compact, adjustable swivel chair

Key specifications

• Model: Topstar SI59UG20 (SI59U G20)
• Seat type: ergonomic Orthositz, Sitness 25/40 mm (10")
• Upholstery: black fabric, 100% polyolefin
• Armrests: U2 type (included)
• Mechanism: permanent contact
• Base: steel five-star with casters
• Seat height: 420–550 mm
• Overall dimensions (W x D x H): 480 x 440 x 420–550 mm
• Backrest height: 580 mm
• Maximum load: 110 kg
• Brand / MPN / EAN: Topstar / SI59UG20 / 4014296541280

How to use

Adjust the seat height using the gas lift lever to position your thighs parallel to the floor and your feet flat. Use the permanent contact mechanism to set the backrest angle that maintains contact with your back while allowing slight recline. Position the U2 armrests so your shoulders remain relaxed and forearms rest comfortably while typing. Use the casters to move smoothly between work areas on suitable floor surfaces.

Usage recommendations

For prolonged daily use, combine correct seating height and lumbar adjustment with regular short breaks and occasional posture changes to reduce fatigue. Check floor type compatibility for the chair casters; use a mat on delicate floors if needed.