1158 Bulb 6V 24 LED. Works either 6 Volt positive or negative ground. Approximate size is 1.57in x 1.03in. Up to 180 Lumen output. Works great for older pre World War II vehicles. Available in White 6000K. Dual filament BA15D base. If tail light comes on brighter than brake light must rotate the bulb 180 degrees. Comparable to a 20 to 25 Watt incandescent bulb. The base is BA15D which means there are two contacts on the bottom. The bayonets are parallel. If the tail light is brighter than the brake light please rotate the lamp 180 degree's. Uses around 1.8 watts. The Lumen output for low is up to 160 Lumens. The high is up to 210 Lumens. The low beam side firing is up to 40 Lumen. The low beam forward firing is up to 120 Lumens. The high beam side firing is up to 53 Lumen. The high beam forward firing is up to 110 Lumen. This lamp is a good choice for older cars that the generator has a hard time lighting the current old incandescent. The light is non polarity so it can work either AC or DC.