No polarity, non polarized or bi polar. The led headlight is designed for both positive ground or negative ground. BA15S base single contact. Super bright up to 1,200 Lumen. Headlight has aviation aluminum to keep the leds cool so they last longer. Wide voltage 5 to 30 volts AC or DC. The LED's are CREE 2525. The circuit board is super conducting aluminum. The headlight uses wide voltage and a constant current design. The leds are on both side so the led will project light into the housing. The base diameter is 15mm and has a single contact. The bayonets are the same height. Available in White 6500k. Long life up to 30,000 hours. Comparable to a 45 to 55 Watt incandescent bulb. The current consumption is 800mA. The socket is made of copper for maximum conductivity.