[Compatible with 146MT574 Timer Knob]Designed for seamless compatibility with 146MT574 and FD Series spring wound timers, this replacement knob ensures a perfect fit and easy installation without the need for additional tools. Its robust construction prevents wear and tear, enhancing the longevity of your timer. [Precision Engineered for Stability]With an outer diameter of 1 inch and a D-shaped shaft of 3/16 inch, this timer knob is meticulously crafted to ensure a stable, tight connection that prevents slippage or wobbling during use. It offers precise control over your timer settings for optimal performance. [Highly Durable and Visibly Marked]Constructed from high-strength ABS+PC materials, this 4-pack timer switch knob set resists heat and impact effectively. It maintains its integrity over time without cracking or deforming. [Versatile Application Across Devices]Ideal for a wide range of applications, these knobs are perfect for timer lights, ceiling fan heaters, fireplace stove fans, whole house fans, attic fan timers, bathroom exhaust fans, and heater timers. They provide a reliable solution for managing various devices in your home or office. Color: White Material: plastic Package Contents: 4* Timer switch knob