If the laser head needs to be lit for a long time, please increase the current limiting resistance appropriately 1. Never point the laser to yourself or others' eyes at any time. Even if the laser is turned off, it may be turned on by mistake. 2. The laser cannot irradiate any reflective surface or smooth surface. The laser has excellent reflectivity. It will reflect when irradiating the reflective surface. If it happens to irradiate people's eyes, it can cause injury. 3. The laser is not a toy and should not be used by children, people with incomplete intelligence and people who do not understand the characteristics of the laser. In this case, it is very easy to cause injury. 4. Wear special goggles when using the laser, especially for invisible laser. 5. The laser cannot shine on vehicles, aircraft and other manned vehicles. 6. Pay attention to the safety of laser battery to prevent short-circuit combustion or battery explosion caused by others removing the battery. The particularity of laser emission principle and generation process determines that laser has the characteristics that ordinary light does not have: three good (good monochromaticity, good coherence and good directivity) and one high (high brightness). Product Name: Laser small copper head (red light) Transmitting power: 5MW Service life: more than 1000 hours Spot mode: point spot, continuous output Laser wavelength: 650nm Power: 50mw Voltage: 3V Current: < 20mA Operating temperature: - 36 - 65 Storage temperature: - 36 - 65 Spot size: 15m 10mm- 15mm It is mainly used for laser toys, various levels, ground wire meters, etc. the laser head is composed of three parts: luminous tube core, condenser lens and copper adjustable sleeve. When sent to the user, these three parts have been assembled, the lens focal length has been adjusted, and has been glued with strong glue. The user can work by connecting 3V DC power supply. Theoretically, in the ideal case (no dust, no smoke, no obstacles), the transmission distance of laser is infinite. Under the condition of high air quality, when the laser head gives 20mA working current, the transmission distance can reach more than 1km. It can be clearly seen on objects 200 meters away at random on cloudy nights For closer distances, even in the daytime sun, it is clearly visible on outdoor roads and buildings. Making electronic pointer pen: when teachers give lectures, they use laser projection points to remind students to observe and think. Electronic level ruler: let the motor drive the smooth head to rotate or twist and project it into a straight line on the wall for horizontal reference when decorating or posting new year pictures. Micro LCD projection: remove the condenser and let the laser pass through the controllable LCD screen to produce a clear projection on the wall. Long distance laser monitor: let the laser irradiate on the glass of the eavesdropping room, then receive the laser beam reflected from the glass, detect the vibration of the glass and restore the sound of the room. Remote light controlled anti-theft alarm: install a laser emitting tube and photosensitive resistor at one corner of the fish pond or watermelon field to be protected, and install a reverse mirror at the other three corners to form a protective area. Long distance laser wireless communication: use a pair of laser transceiver devices to face each other on the roof of two distant houses, and use the serial communication protocol of single chip microcomputer to send and receive files and even connect to the Internet.