More than 400 independent clinical studies have proven that the UVB Narrowband treatment is safer and more effective than any other treatment in its class. Lamps installed in such phototherapy treatment systems emit only a very narrow waveband from the ‘B’ bandwidth of the UV spectrum (290 to 315). Philips offers lamps with narrow waveband of between 305 and 315 nm which peaks at 311 nm. This makes these lamps very suitable for Clinical and Home UV-B Narrowband phototherapy systems which treat skin diseases such as psoriasis and vitiligo.N.B.: Our UVB lamps are NOT registered with FDA as medical devices as they are NOT packaged or labeled for commercial distribution for health-related purposes. US customers are referred to the UVB and UVA lamp range brochure US version.