Rubberized wheels are especially convenient for use on hard surfaces (parquet, laminate or tiles), as they protect it from scratches and damage, reduce floor wear and ensure more comfortable movement without unnecessary noise. Unlike hard plastic wheels, they do not slip, grip the surface better, and do not leave marks.
The ability
to change the backrest tilt back and forth. Allows users to adjust the chair depending on how they prefer to sit: straight or slightly leaning back.
Depth means the location of the seat in a horizontal plane - how far it is pushed forward, or, conversely, "pressed" under the back. Accordingly, the distance between the back and the front edge of the seat essentially depends on the depth; and
seat depth adjustment allows you to adjust this distance so that the seat does not rest against the knees and at the same time provides enough space for comfortable placement in the chair.
The material from which the base of the chair is made (see "Base construction").
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Plastic. Plastic is notable for its low cost, combined with ease of processing — it can be easily given even a rather complex shape. This material is considered less durable than metal, but modern plastics are able to provide sufficient strength even for chairs designed for high loads (see "Maximum user weight"). However this is true only for bases of the "cross" type; for the legs and skids, the plastic is still not strong enough. However, it is found in models of all price categories.
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Metal. The main advantage of the metal is its high strength, due to which it can be used for all types of bases. At the same time, it is somewhat more expensive than plastic, and therefore, among armchairs with a cross, it is found mainly in models of the middle and higher levels.
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Tree. Wood can be attributed to design materials: it is used not so much for practical reasons as to provide the chair with a stylish and aesthetic appearance. At the same time, it is considered more reliable than plastic (although not as reliable as metal), so it can even be used for skids. However chairs with wooden bases are quite expensive.
