Use this 12-watt power supply to power up to (16) low voltage post caps. This 12-Watt Power Supply uses a 9’ wire lead and includes a Tee connector and a female connector. To determine what power supply you should be using, add up the total wattage of all the bulbs you want to power. This estimate will indicate what size transformer you will need. This power supply’s maximum is (16) 0.8 watt lights.