A supercharger pulley puller is used to remove and attach the pulley to a supercharger. Unless the puller has become damaged from improper use, a pulley puller should last a lifetime. The supercharger pulley may need to be replaced from time to time, especially if the pulley was made from a soft metal like aluminum. Supercharger pulleys spin at very high rates, close to 1/8 miles per hour, and because of their small size, are prone to wear from belt damage. A steel pulley, while heavier, will be more durable and will last longer.
For more info, see Supercharger Tuning Made Easy