This portable UV light provides 4 watts of illumination that can help to isolate suspected stains on large areas such as bedding, furniture, or automobile interiors.
However, a UV light CANNOT conclusively identify a semen stain or any other kind of stain because everything including toothpaste, coffee with cream and sugar, urine, and even the brighteners found in many of todays laundry detergents will all fluoresce when subjected to U.V. or "black" light.