Andersen Window - Operator, Casement, Wood, Split Arm, PSC, Stone - RAndersen Window Operator, Casement, Wood, Split Arm, PSC, Stone R Andersen Window Split Arm Operator with Screws Note: When changing from straight arm operator to split arm operator, both head and sill hinges must be replaced to operate sash properly. White and stone hardware use the same operator. Handle must be purchased separately. Stone operator comes with the operator cover. If you need a white operator cover, order it separately.