Feature 1OE Number: The referencing OE number of this all lamps module is ALO 37, which is molded and designed depend on the original data. 2Fitment: The all the lamps on module is a replacement for 2003 to 2007, please check the model and year before ordering. 3Main Function: Control high beams, low beams, fog lamps and day time running light to be on simultaneously when turn on high beams. Greatly improve illumination at night. 4Durable Construction: The all the lamps on module is made of high performance PCB Materials, which is solid in construction, durable and much safer to use. 5Easy Install: Find your fuse box, pull out 4 relays labeled Fog Lp, Hdlp Low, Hdlp Hi, Drl. Lay down the circuit board and reinstall those relays back into original location. No modification to existing wiring.Item Type:AllTheLampsOnModuleOENumber:ALO37 .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Material: PCBFitment:Fits for1500/2500 HD 2003-2007, for3500 2003-2006, for2500 2003-2004, for1500 HD 2005-2006, for 1500 Classic/1500 HD Classic/2500 HD Classic/3500 Classic/3500 HD 2007, for1500 HD2003Replacement for1500/2500 2003-2006, for1500 HD 2003, for1500 Classic/ HD Classic 2007, for2500 HD Classic 2007, for3500 Classic/3500 HD2007Fits for2004-2006, forEXT2003-2006Fits for GMT800 GMT 800 trucks20032007Package List1 x All TheLampsOnModuleNotePlease double check the part number of your item, matching information is for reference only.Low beams fog lights and DRL will function normally, when the high beams are not turned on.