Discover the hidden rarities in your collection with this best selling handheld tool. The Stanley Gibbons Detectamark Spectrum makes it even easier to discover the hidden rarities in your collection. This battery powered device operates via pressure applied evenly to the stamp by means of a recessed screw in the base of the device (AA batteries not included). It is simple to use and the multiple colour settings and adjustable light source, unique to the Detectamark Spectrum, provide additional help when identifying more difficult watermarks.