In 4 Watt 6 Inch Category, two brands UV Lamp are available. One is of Phil-ips TUV 4 Watt G5 & other is Osram Germicidal Puritec HNS G5 4 Watt. The customer can select either one of them while placing the order. This UV Lamp emits the UV - C type Radiation of frequency 254 nm (Nano Meter), which is more than sufficient to kill any biological germinations of virus, bacteria, micro-organisms etc from the feed water supply. This UV Lamp is compatible with Water Purifier machine of Aquaguard, Aquasure, Havells, Livpure, HUL Pureit, Hindware etc etc. Osram or Phil-ips make lamps are originally factory fitted in Water Purifier machines of these brands. Osram make UV Lamps are manufactured in Italy, where Phil-ips make UV is manufactured Poland.