Small, lightweight lamps are ideal for use anywhere. Choose from single- or dual-wavelength models. The dual wavelength 9760202 97602-20 has a wavelength selector for choosing 254 or 365 nm light. Lamps include one 4-Watt tube and measure 6-1/2"W x 1-3/4"H x 1-1/4"D. Product may contain trace amounts of mercury; cautions should be used in breakage, cleanup, shipping and/or disposal. What's included: one 4-Watt tube and a nylon strap. Order batteries separately. Compact - fit right in your pocket average bulb life is 3000 hours.