Back nylon back chair surface PU leather armrest PP material integrated armrest sponge shaped sponge tray self loading tray air pressure rod SGS certified air rod five-star foot steel caster PA black nylon wheel The body does not leave the chair waist, does not leave the back, and the intelligent waist protection function can be "leaned" no matter how C-arc widened and enlarged headrest gently supports the head and neck arc wrapped headrest, and the posture and angle can be changed freely without restraint The saddle shaped cushion increases the wrapping feeling of the hip, ergonomic saddle shaped arc design, and the waterfall shaped seat fits the thigh to alleviate the discomfort of sitting for a long time