Abstract: A chair mat includes two first flat panels having sufficient rigidity to support a chair with a person therein. The panels have abutting straight panel edges. Flexible fabric is permanently adhered to and fully covers one side of the abutting panels. The other side of the abutting panels has an anti-skid surface provided by the panels themselves or covering material not essentially providing tensile strength across the abutting straight panel edges. A material strip extends the length of the abutting first and second straight panel edges permanently adhered to the panels between the flexible fabric sheet and the panels with high tensile strength filaments oriented laterally of the material strip.

Abstract: A chair comprises an arm mechanism and a back mechanism each having an adjustment screw for releasably securing a sleeve and a shroud to a J-bar so that a height of either arm or back mechanism can be adjusted relative to the j-bar. Also, a protruded enlargement is formed at a top end of the upright backrest support.