IP67 refers to the level of protection security. IP is an abbreviation for Ingress Protection Rating (or International Protection code), which defines an interface's ability to protect against liquid and solid particles. IP followed by 2 digits, the first is the solid state protection level, the range is 0-6, respectively, indicating protection against large particles of foreign matter to dust; the second is liquid protection level, the range is 0-8, respectively Protection against vertical water droplets to underwater pressure. A larger number indicates a stronger ability. IP67 is explained by the protection of dust inhalation (to prevent contact overall, to protect against dust penetration); to protect against brief immersion (anti-immersion).