This is a universal break-off link arm that makes it possible to adapt to whatever length link arm is needed when installing a louver or jalousie operator. Made of cadmium plated steel, it has break-off points between holes every 1/2 in. . This allows for a range from 1-13/16 in. to 5-5/16 in. in length. Any one of the lengths in between this range will be adequate for most situations.