This Ellipse single arm casement operator is constructed of a diecast body, a hardened steel arm (with a steel guide button at 9/16 inch in diameter), and a case-hardened worm gear mechanism that comes in a corrosion-resistant coating. It features a contoured-edge housing and an operator crank handle that come finished in a white colored baked-on enamel finish. This casement operator is left-handed, determined when viewing the window from the outside looking inch Operator is a surface-mounted crank-out design for casement windows and mounts with six fasteners. This high-end quality operator exhibits minimal gear lash, with positive and smooth operation. Installation fasteners and a set screw (for affixing the crank handle onto the operator spindle) are included with each operator. This operator provides a full 90-degree opening and disconnects easily from the sash.