Sylvania 51481 - QHE4X54T5HO/347-480 PSN HT SCL T5 Fluorescent Ballast specifically designed for high ambient temperature applications Utilizes Programmed Rapid Start operation for: Highest System Efficacy & Longer Life Over 100,000 switching cycles for occupancy sensor and building control systems applications helps to protect against overheated bases and sockets, as well as cracking of the glass wall