The A Foot-Ring is a slim, ingenious design. Most foot rings are fixed on the chair tube by a screw, but this leads to a potential sliding risk if the screw comes lose, as it inevitably does. This product has a unique plastic bushing mechanism, so the con-shaped structure provides resistance by itself, steady and safe. Without the traditional screw-knobs, a chair also becomes more attractive. By simply pressing the top of the plastic bushing, you can adjust the height easily and at will.