Your Bags on Board Dispenser comes with a roll of bags inside as well as a roll of refill bags. To use, simply pull out a bag and release at the perforation. Place your hand in the bag and pick up the waste. Then invert the bag, inside out, and tie. Please dispose of the soiled bag properly. To replace with a new roll of bags, just pop off the lid, remove the used bag cartridge and refill with a new bag cartridge. Replace the lid and you're ready to go. Caution: Plastic bags can be dangerous. Keep out of reach of children and pets.