This is a jalousie operator that has a aluminum finish, diecast construction. Mounting holes are 4-3/4 in., or 3-7/8 in. on center. It has a reversible, non-handed design that can be used on either left or right-handed installations. The 3 link arms come 3-5/16 in., 3-5/8 in., or 4-1/4 in. in. long to accommodate different needs of installation. A matching T-handle that fits the 5/16 in. spindle is included.