Philips tuv pl-s11 watts single tube 2-pin g23 base uvc germicidal fluorescent bulb tuv pl-s lamps are compact uvc germicidal lamps used in residential water and air disinfection units. The compact size of the lamp allows for a small system design and design flexibility. Tuv pl-s lamps offer constant uv output over their complete lifetime, for maximum security of disinfection and high system efficacy. Thanks to the single-ended lamp base, lamp replacement is easy.