Swift Taillights Provide Instant Taillights for Any Vehicle or Trailer Being Towed. Use it on: Farm Trailers & Hay Trailers, RV's & Campers, Horse Trailers, Construction Equipment, Boat Trailers with Water Damaged Wiring and Utility Trailers. Digital Communications Between Controller and Taillights to Avoid Interference. Re-chargeable Battery with Runtime up to 6 Hours and LED Long Lasting Bright Red & White Lights. Swift Taillights are intended for temporary use only. CONTROLLER - One-Button Control of Taillight Signaling, including: Stop, Forward, Left & Right Turns, Reverse, Emergency, Flashlight Mode, Digital Communications Between Controller and Taillights to Avoid Interference, Transmitting Distance Between Controller & Taillights Up to 100 Feet, Taillight Battery Low Level Indicator, Re-chargeable Battery with Runtime up to 6 Hours