12V-24V Flash Strobe Controller Flasher Module for 3rd LED Brake Lamp Tail Stop Lamp (Pack of 4) Size: 4PCS About this item Package of 4 PCS Auto Flashers Module for 3rd Brake Light Tail Stop Light Working Voltage: DC 12V - 24V, suitable for all motor vehicles, motorcycles, electric bicycles, or LED bulbs installed with the third brake lights. Connection: Black wire for negative pole and red wire for positive pole (note that it has 2 sides; "In" must connect with power supply and "Out" must connect with bulbs). Improves traffic safety warning to help avoid rear-end accidents. When driving at night, during foggy, or rainy days, the flasher produces a visual alert signal. Completely sealed, waterproof, and includes short circuit protection. The flasher will make the brake light function with fast-blinking 4 times, then slow-blinking 4 times. When flashing is completed, it will remain in the original steady light. Dimensions: 7.72 x 4.49 x 0.71 inches.