1.Casters: General castors, PU wheels (soft materials, suitable for wood flooring, and engine room).
2.Chair legs: The thickness of the iron frame directly affects the service life of the chair. Surface treatment: polishing, painting, paint (surface gloss, not easy to paint stripping), electroplating (wood frame can not be electroplated), plating quality is good, it is not easy to rust.
3.Gas lift: used to adjust the height and rotation of the chair.
4.Mechanism: Hold up the part of the seat and connect it with the gas lift below.Locking and tilt.
5.Seat: consists of plywood, foam, fabric composition. The quality of the plywood is usually not felt by consumers. Foam: renewable cotton, new cotton. 99% of manufacturers are using the two together；fabric: polyester, mesh, leather. Or with Plastic shell. This type of chair is more breathable.
6.Armrests: thickness affect the quality.
7."L" metal support for back & seat connection : chair seat and back are separate, using steel or steel plate connection, steel plate, usually 6mm or 8mm thick. However, steel plates with a width of less than 6cm must be 8mm thick.
8.Backrest: steel frame or plywood frame,made with a combination of mesh, with breathability or leather + foam.
9.Lumbar pillow: reflect the comfort of the chair.
10. Headrest: Express the comfort of the chair.