# Office chair Topstar Sitness 40 ST290W51 Red — ergonomic design, adjustable height

**URL:** https://aio.lv/en/product--topstar-st290w51--1493107
**Data updated:** 2026-01-13 15:39 (EET)
**Category:** Ergonomic Chairs
**Manufacturer:** Topstar
**Manufacturer code:** ST290W51
**EAN:** 4014296112428
**Warranty:** 2 Years
**Availability:** Out of stock

## Summary description

Topstar Sitness 40 ST290W51 is a red office chair with an ergonomic design and adjustable height. Designed for daily desk use, it supports active sitting and posture through a flexible seat mechanism. Suitable for home and office environments, the chair offers basic comfort and mobility, facilitating longer sitting periods with improved back support.

## Long description

Topstar Sitness 40 ST290W51 Red is an ergonomic office chair designed for daily desk use. The chair features a flexible seat mechanism that promotes active sitting and supports natural posture adjustments. With adjustable seat height and a contoured backrest, this red office chair is intended for home and office environments where users need reliable basic comfort and mobility during extended periods at a workstation.
Advantages
The chair’s sitness mechanism encourages micro-movements of the pelvis and spine to reduce static load on the lower back. Height adjustment allows adaptation to different desk heights and user sizes, while the contoured seat and backrest provide simple, supportive seating. Smooth casters and a swivel base enable easy repositioning and access to surrounding work areas without standing up.
Suitable for
Home office work and study
Standard office desk tasks and meetings
Short to medium duration computer sessions
Users seeking a compact ergonomic chair with mobility
Key specifications
Ergonomic sitness seat mechanism for active sitting
Adjustable seat height via gas lift
Contoured seat and backrest for lumbar support
Swivel base with rolling casters for mobility
Upholstery in red fabric
Suitable for standard desk heights and typical adult body sizes
How to use
Adjust the seat height so that your feet rest flat on the floor and your thighs are approximately parallel to the floor. Sit with your back against the contoured backrest to take advantage of the sitness mechanism: small forward and backward movements of the pelvis are allowed and supported to reduce stiffness. Use the swivel and casters to reach items around your workspace without twisting your torso excessively. Avoid prolonged static postures by changing position periodically.
Usage recommendations
For best results, combine regular posture changes with short standing or walking breaks. If multiple users will use the chair, adjust seat height before each session to maintain ergonomic alignment. Inspect the casters and gas lift periodically for smooth operation and safety.

## FAQ

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Topstar products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Topstar service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/1493107/59842184_large.webp