1. If measured in a poor measurement environment(such as a strong light environment), terror is approximately ±1mm + 40ppm
2. Use a reflector or A4 paper when measuring at a strong light environment or low-reflecti target point
3. Don't look at the laser. There is a high probability of hurting your eyes
4. Please do not use it outdoors. Only for indoor use
5. Dark reflective surfaces and walls may not be measured, please use it with the help of li color reflectors