Seat sponge : PU sponge molded by cold foaming,the density is at least 40Kg/m3 , • Back sponge : PU sponge molded by cold foaming,the density is at least 40Kg/m3 • Back shell: High quality PP shell by mold molding • Seat shell: High quality PP shell by mold molding , ; • Fabric :Applied high quality linen fabric ,positioning the chair back with string and adding mercerized cotton ; • Leg:2.0mm steel plate , with inlaid side panels , The height of the lower end of the front of the armrest frame: • Writing table: The support rod of the writing board is a solid steel bar φ14mm • Recovery function: spring recovery mechanism Screw: expansion nut + screw;