Philips TUV PL-S 13W/2P Germicidal Light Bulb (9279 028 04007)TUV PL-S 13W/2P 1CT/6X10BOX*** UPC 8711500867230 is for 1 pc From PHILIPS ****** UPC 8711500867247 is for Carton with 10 pcs From PHILIPS ****** UPC 8711500867254 is for Carton with 60 pcs From PHILIPS ***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 singleended lamp base, lamp replacement is easy.