BA15D 1158 6 Volt 60 SMD 5730 Dual Filament Reduced Profile. This bulb operates 6v positive ground or 6V negative ground. Up to 900 Lumen output for brake light and up to 500 Lumens for tail light. Up to 340 forward firing Lumens and 560 side firing Lumens. Long life up to 30,000 hours. Made with total 60 leds, 44 side firing and 16 forward firing. This lamp is a two filament bulb. The base has even bayonets and two contact on the bottom. This bulb is only designed for 6 volt vintage vehicles, motorcycles and scooters. Please make sure you voltage is regulated to 6 volts. The light bulb can be dimmed with a variable voltage supply if needed. The leds are aligned to be the optimum height for maximum light output using a reflector and lens. Available in White 6000K, Warm White 3000K, Red and Yellow. Maximum overall length is 1.694". The maximum diameter is 1.058". These lights led are solid state for low power and super long life. SMD means surface mount device it is the square led. Uses about 1A @ 6.3 Volts for the brake light. CE and Rohs.