Philips 9 Watt Air Purifier UV Light In Duct Replacement Bulb -10,000 Hours Lifetime! Wattage: 9 Watts Bulb (glass) length (not including plastic end) for 9 watt= 5" (12.7 cm) V-C LIGHT GERMICIDAL RREPLACMENT FOR BIO MED HI TECH UNITS, R18, R18W, R18D & D100, D200 & A200 Produces UV-C (253.7 nm wavelength) radiation