This DENALI Data Dim™ Dual-Intensity Controller enables the DENALI lights to switch between half & full intensity with your vehicle’s original high beam switch. All DENALI 2.0 Light pods are equipped with a dedicated 3rd-wire dimming circuit so an external signal can reliably control the intensity of the LED chip at the source. This will allow you (for example) to couple your dipped-beam headlamps to 50% mode & your main beam to 100% mode. Warning, if you want to control the intensity of your lights separately from the rest of your equipment, you will need to install the 3 position switch 30500042 Article: DENALI 2.0 Data Dim Dual Intensity Controller