HQUA-EBS51-425-40L Countdown Timer Electronic Ballast. Compatible with HQUA-OWS-12L and HQUA-OWS-6L UV lamp. The product has three operating features: pre-heating start; indicator alarm and buzzing; lamp life timer (count down) and ballast cumulative work timekeeping (positive timing). The product consists of three parts: the input and output lines and the host box. The host box contains: indicator part, nixie tube, and button for human-computer interaction. The usage of this product is simple and clear, please read the following operation manual carefully for all the necessary information.