cciyu 5X T10 194 Ice Blue 4-3528-SMD LED Bulbs for Clearance Cab Marker Lights lamps 2012 Ram 2500 6.7L 5.7L 3.5L For Roof Running Cab Marker Clearance Light lamp (blue) Built-in Circuit for 12V Power Input.Smaller in size,great for applications in most vehicle,common use Long-lasting Life - 50003 working hours.Easy installation, No modification needed. Just plug & play Cross Reference: Cross Reference / Compatible socket bulb number: Direct replacement for all Wedge Type T10 Wedge Bulbs = W5W W3W 147 152 158 159 161 168 184 192 193 194 259 280 285 447 464 501 555 558 585 655 656 657 1250 1251 1252 2450 2652 2921 2825 PC 175 2886X Application: Cab Marker Clearance Light, Roof Running Light. If the LED does not light up, simply Rotating it 180 degrees (reverse the polarity)