This refill cartridge of serum - for use with GLO24K Red LED Light Beauty Wand - The Rejuvenator - means that you will never have to go without the age-defying benefits of this All-In-One Beauty System. Simply replace an empty cartridge with a new one and unlock the benefits of this Serum coupled with RED LED Light. Remove the cap at the top end of the wand. Twist off the centerpiece cylinder counterclockwise to detach it. Push down the nozzle and replace it with a new cartridge. Reassemble. Discard the old empty cartridge. Use Serum as needed. For all skin types.