Using this Simpson Maxidry dryer timer knob is simple. Just align the knob with the two - flat - sided shaft of the timer in your dryer and gently press it on until it's firmly in place. When using your dryer, turn the knob to set the desired drying time as you normally would. As for maintenance, it's a good idea to keep the knob clean. You can use a soft, damp cloth to wipe it down occasionally to remove any dust or debris. One important thing to note is to make sure the dryer is unplugged before attempting to remove or install the knob. This will help prevent any electrical accidents. Also, avoid using harsh chemicals or abrasive materials on the knob as they could damage its surface.