The diameter of the curtain rod bracket is 25mm/26mm/28mm/32mm/35mm respectively, the larger the diameter, the thicker the rod. At present, the market on the 28mm diameter of the pole more, most of the family to choose is this, if do perforated curtains, more than 32mm pole need to use a special large ring, will increase the extra expenses, iron rod diameter to small, so the visual feeling slim.