Sihoo M18 Ergonomic Office Chair, Computer Chair Desk Chair High Back Chair Breathable,3D Armrest and Lumbar SupportHigh Quality The gas lift of high back office chair has been certified by BIFMA and SGS and has passed the static pressure test of 1136 kg. Our desk chair can support a weight of up to 150 kg. Simple instructions enable anyone to put chair together in eight simple steps. Patterned Mesh & TPU Armrests The chair features a patterned mesh as the picture shows, that is not the same as another M18. What is more, the surface of the armrests of the chair is