A device for stimulating hair growth applied to a user’s scalp. An apparatus includes a secure enclosure housing a reservoir of tennis balls, a battery power supply and a battery powered portable tennis ball machine, the secure enclosure and tennis ball machine communicating via a wireless network to determine a location of the portable tennis ball machine. The retailer also receives customer-based information from the customer. The third spool has a leading end portion and a second catching mechanism secured to its leading end portion.