HQRP 2-Pack UV Germicidal Sanitizer Bulbs for Vicks V790 V3900 plus HQRP Coaster HQRP&reg; 2pcs UV Germicidal Sanitizer / Sanitizing Bulbs plus HQRP&reg; Coaster; Base: E17 Intermediate Screw; 3 Watts UV-C bulb; 100% Ozone Free Short-wave UV radiation with a peak at 253.7 nm (UVC) for disinfection purposes. Energy efficient light bulb. 200 days warranty!