These brackets made of plastic and stainless steel can be used with all of our lag mount shutter dogs. Fits up to a 3/8" diameter lag bolt and is easy to adjust. The brackets hold the shutter panel and dog together firmly to reduce rattling in the wind. The distance from the center of the lag bolt to the edge of the shutter must be 1 1/2" or less for these to work. The tube portion slides over the shutter dog lag bolt on the back side of the shutter. It is locked in place with a small set screw. The knob is then tightened against the back of the shutter to keep from rattling.