The Lascells Dual Colour semiconductor laser box contains two independently controlled laser diodes one at the standard 650nm red and a second at 532nm green. Both lasers may be simultaneously passed through a double slit slide and both diffraction patterns may be displayed one above the other for an immediate comparison.The unit is equipped with internal 1 MHz modulation which when used in conjunction with the laser receiver and an oscilloscope allows the speed of light to be determined in the laboratory. In addition the facility to modulate the laser from an external source is provided allowing audio to be sent to the receiver from a smartphone or mp3 player.The apparatus is switched using a removable key which prevents unauthorised use and is supplied with a 9V power supply and full instructions.Technical Specifications:Power Output: <1mW max.Laser Class: Class 2Laser Wavelengths: Green - 532nm (+/-5nm) Red - 655 (+/-5nm)Beam Divergence: Green - 1.5mRad Red - 1.5mRadInput Voltage: External 9V D.C. power supply: +ve pin (Included)Modulation: 1Mhz internal audio frequencies externalDimensions: (L)150mm x (W)110mm x (H)65mmWeight: 390g.