More than 400 independent clinical studies have proven that the UVB Narrow band 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.