Restore smooth operation to older steel-framed casement windows with the Prime-Line H 3520 Right-Hand Casement Operator. Designed as a replacement for worn, damaged, or difficult-to-operate window mechanisms, this operator helps restore reliable opening and closing performance while maintaining proper window control. Commonly used on older steel-framed casement windows, it mounts on the right side of the window when viewed from inside the home looking outward.Constructed with a durable diecast housing and crank handle, this operator is engineered for long-lasting performance and dependable daily use. The assembly features a 9 in. hardened steel arm and a precision worm gear drive mechanism that delivers smooth, controlled sash movement. Finished in a corrosion-resistant aluminum-painted coating, the square-body operator provides durability while matching many original window hardware styles.This replacement operator installs using two mounting hole patterns spaced at 3-7/8 in. and 4-3/4 in. on center, allowing compatibility with a variety of older casement window applications. A matching crank handle and installation fasteners are included for a complete replacement solution. Before purchasing, compare the mounting pattern, arm length, housing style, and spindle configuration to your existing operator and review the line drawing to ensure proper fit and compatibility.