Using this soap dispenser is easy. First, install 4 D-Cell batteries into the battery pack (batteries are not included). Then, insert the soap cartridge into the unit. The dispenser will start working automatically when your hand is near the sensor. Keep an eye on the LED indicator. If it blinks red, it's time to refill the soap. If it blinks yellow, change the batteries. When refilling the soap, you can choose between 27-fl oz (800ml) and 54-fl oz (1600ml) cartridges. The motor can be adjusted to fit different cartridge shot sizes. To maintain the dispenser, clean the spout regularly with a soft cloth. Avoid getting water into the battery compartment to protect the water-resistant motor. With proper use and maintenance, this dispenser will serve you well for up to 2 years or 100 soap refills.