Features Proprietary durable phosphor coating, for uniform solid appearance Multi-function PWM drivers, fully waterproof, featuring low power, high power, and turn signal modes Extremely bright, high-density LEDs that are visible even in direct sunlight Integrated mounting tabs for easy installation Assembled in the USA Overview HDHalo Technology. These HD LED halo rings have been designed from the ground up to be absolutely the brightest, most reliable halos physically possible. Each halo is populated with a large number of high-density (HD) LEDs, which are then coated by a diffusing gel, resulting in a perfectly uniform light when turned on. When off, the diffusing gel hides the chips, resulting in a clean, OEM appearance. Sizing: All sizes are listed by outside diameter, in millimeters. The width is 8mm, so the inside diameter is 16mm less than the outside diameter. Total height is 4.5mm. Mounting: The halos must be custom-mounted in position using adhesive or beading wire using the integrated mounting tabs. If you wish, mounting tabs may be removed with a pair of clippers or basic sanding. The halos can be modified if needed to fit certain applications. Up to 20% of the halo can be removed using side-cutting snips and remain fully functional. Wiring: All wires have a durable braided wire covering. The LED has a 20-inch wire with a female JST-type connector. This connector may be de-pinned to run wires through small holes during installation. Both the input and output wires on the driver are also 20 inches each. A pigtail is included that is also 20 inches, with male spade connectors on the end to connect to factory wiring with included T-taps. You will have plenty of room to run wires anywhere you'd like. PWM Control: Aside from the high brightness and perfectly uniform output, one great feature of these halos is the integrated multifunction PWM dimming control. The drivers have four wires to be connected to any 12V signals as follows: White: White Low Power, 50% brightnessRed: White High Power, 100% brightnessYellow: Amber Signal, double brightness, flashing (dims if powered for more than two seconds)Black: Ground All input wires activate the halos at different brightness levels. All switchback halos ship with "low" priority drivers. This means that if both "low" and "high" power inputs are powered, the LED will light up in white, with a low power level. This is convenient for connecting the red wire to a parking light or DRL signal, for use during the day as a high-power DRL. Then, if the white wire is connected to the headlamp power, they will dim down at night. If the yellow wire is powered at any time, the halo will light up in amber color, intended for signaling. If you'd like to use amber all the time, no problem! It will dim automatically if powered for more than two seconds, to keep it safe. This entire setup allows you to connect the halo directly as a multifunction lamp, without any external controllers needed. Of course, this is completely optional. You can just use one or two of the input wires if you'd like. Experience. After over a decade in business, Diode Dynamics is the most trusted name in automotive LED lighting. Unlike every other LED distributor, we assemble and engineer products ourselves in the United States, for high quality and fast time-to-market of the newest and brightest LED technologies. We pride ourselves on offering only quality LED products that will exceed your expectations. Please contact us if you'd like to discuss your lighting project! What's Included In the Box: Two (2) LED halo rings Two (2) waterproof drivers Two (2) input wire pigtails Eight (8) T-tap connectors Installation guide Fitment Note: Depending on the installation location and proximity to other electronics in your vehicle, this product may cause radio interference at certain frequencies.