The 44MG90-06-1-02N is a non-turn washer accessory designed for use with Grayhill Series 42, 43, 44, 54, and other rotary switch models. This component features a brass construction with tin/zinc plating and incorporates a keyed design where an internal key slides into the bushing keyway to prevent rotation. The washer includes a right-angle tab that locks into a predrilled hole on the back side of the mounting panel, ensuring secure and stable mounting. With a diameter of 0.625 inches (15.88 mm) and a bushing keyway width of 0.066 inches (1.68 mm), this accessory provides reliable panel mounting for rotary switch assemblies. The non-turn washer is commonly used in industrial control panels, instrumentation, and military-qualified applications where switch position stability is critical.