Applications For retrofit onto windows with Truth operators. WLS motors can’t be wired in parallel to operate multiple motors. WLS must be mounted to a Truth window or skylight operator; the motor replaces the manual handle. WLS applications – for wood, PVC or metal sashes: Casement windows meeting AAMA-101 hardware load specs. Awning windows with appropriate loose-rivet type hinge and operator. For skylight weighing up to 80 lbs (WLS is load-rated at 40 lbs). For skylights: also use a Truth angle drive module, type 42.65, to connect to WLS to a skylight, sold separately.