The UV-B Narrowband PL-L/PL-S family More than 400 independent clinical studies have proven that the UVB Narrowband PL-L/PL-S lamps are safer and more effective than any other lamps in their class. The PL-L/PL-S versions provide additional design freedom for system manufacturers since these are space-saving compact, single-ended lamps. Further flexibility is assured since they use the same lamp caps as general lighting lamps, they also use the same universal ballasts. Their best-in-class treatment effectiveness is a result of their very narrow waveband emission: between 305 and 315 nm with a peak at 311 nm. This is the most efficacious waveband for the treatment of psoriasis, and is therefore much more focused. As a result, exposure times are much shorter and this in turn leads to a reduction of side effects such as reddening of the skin and itching. All of this makes them ideal for phototherapy treatment of diseases such as psoriasis, parapsoriasis, vitiligo, atopic dermatitis, and mycosis fungoides. What’s more, because the overall dosage of this narrowband radiation can be closely controlled, these lamps are suitable for home therapy.