on center.
This is a lever style louver or jalousie operator used on International Series 400 windows. Aluminum, Left-Hand, Louver Operator, International on centerAluminum construction with a mill finishAttaches to the moving arm of the jalousie or louver windowMounting hardware includedA Phillips head screwdriver is required for installationFor further dimensional information, please see the line drawing Mounting holes are 1 in. It is left-handed and is of aluminum construction, with a grooved stud that attaches to the moving arm on the jalousie or louver frame..