Easy taken light product for on-the-spot investigation, so as to fit for criminal spy demand, use the most advanced single wavelength light source, can last 3hrs by normal dry cell, it can display visible wavelength to UV wavelength which are selective light for search. Main use for searching, the dactylogram and footprint searching left at scene; detect the body fluid, poison, pesticide, explosive residual and Censorship, it is the fantastic lighting facility of criminal technicians.