The high-performing TSF 4ft Selectable CCT LED Stairwell luminaire is ideal for stairwells and other general ambient lighting applications. This advanced luminaire uses the more applicable ultrasonic sensor to detect motion that does not require a direct line of sight instead of an infrared sensor. This luminaire is optically engineered for maximum efficacy and optimal light distribution with excellent uniformity. This luminaire is suitable for vertical and horizontal mounting and provides easy installation and long life. Emergency Battery Backup kit available.