Your SEAMLESS LED lighting system is a low voltage lighting system, operating at 24 volts DC to be exact. Your home likely uses 120 - 240 volt AC current. A stepdown power supply (driver) is used to convert your home power to the voltage required. The size and cost of the power supply is determined by the size of your system. So as an example, let's say you need to make a single 10 foot run. Since one foot of the seamless uses 3.4 watts of power, that 10 feet times 3.4 = 34 watts. Your will require a power supply of greater than 34 watts. If your system is a straight run using a plug & play power supply, you would need to purchase the DL-PS-48/24, which would more than handle the 34 watts. It can get a bit confusing, especially with large set-ups, so if you are not sure, email us or Jesco your questions.