Using this Bobrick B - 8263 soap dispenser is easy. First, make sure to install 4 'D' Cell batteries in the dispenser. Once the batteries are in, place the dispenser on your countertop. The maximum thickness of the countertop it can be mounted on is 2 inches (50mm). If your sink rim is 3/4 inch (19mm) or thicker, use the included spacer. When you place your hand within 4 inches (100mm) of the sensor lens, the dispenser will automatically release a controlled amount of soap (0 - 8ml). For soap refills, you can use OneShot® soap. You'll get 1000 hand - washes per 800ml or 2000 hand - washes per 1600ml of the refill. Remember, this product comes as just the dispenser, so if you need a full starter kit, look for B - 8263.18. Keep the dispenser clean by wiping it with a soft, damp cloth regularly. And always store extra batteries in a dry place.