Link Arm with 3/8" Offset This Window Operator has a single top screw hole and two bottom screw holes which are 1-1/2 inches (35 millimeters) on center. The distance between the top and bottom screw holes is 5-1/16 inches (128.6 millimeters) on center. The 3/8 inch (9.5 millimeter) offset link arm is 2-5/8 inches (66.7 millimeters) long and the link end has a 3/8 inch (9.5 millimeter) hole. It fits on Anderson windows. Minimum Order: 1 Package Each package contains one operator. If any replacement parts are needed, please, click the following link: Repair Parts .