For best results use in a dimly lit room against a dark background. This hand held portable model requires 4 AA batteries<br> Short wave Lamp<br> This Short wave lamp will clearly show you the phosphor and the phosphor afterglow on GB stamps up to 1992.<br> For best results use a short wave lamp in a dark room, the darker the room the better.<br> To see the different coloured phosphors on the 1960 Wildings issue its the phosphor afterglow you are looking for when you turn the UV light off,<br> Green phosphor is the brightest (10 seconds afterglow) followed by blue, (15 seconds) the Violet has a very short afterglow (5 seconds) It will be difficult to see the<br> after glow in daylight, the darker the room the better.<br> This two hand held portable model requires 4 AA batteries (Not included)<br> Package Includes:<br> 1 x 254nm shortwave UV lamp<br> Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-DIMEANI official store