Specifications: 254nm shortwave and 365nm longwave UV lamp for fluorescence detection on stamps and banknotes. Note: 4 AA batteries (not included). This longwave lamp reveals various types of fluorescent and colored bands on GB stamps (refer to illustration for blue and yellow). It is also effective on stamps from Australia, Canada, China, France, Germany, Hong Kong, Mexico, Norway, and Russia. The lamp can help identify different paper types such as OCP, FCP, PCP, and ACP. For optimal results, use in a dimly lit room against a dark background. This handheld portable model requires 4 AA batteries. Shortwave lamp: This shortwave lamp clearly shows phosphor and phosphor afterglow on GB stamps up to 1992. For best results, use in a dark room—the darker, the better. To observe different colored phosphors on the 1960 Wildings issue, look for the phosphor afterglow immediately after turning off the UV light. Green phosphor is the brightest with a 10-second afterglow, followed by blue with a 15-second afterglow, while violet has a very short afterglow of approximately 5 seconds. Afterglow effects are difficult to see in daylight; a dark environment is essential. This dual handheld portable unit requires 4 AA batteries (not included). Condition: 100% Manufacturer: China Package includes: 1 x 365nm longwave UV lamp 1 x 254nm shortwave UV lamp