With signal output indicator light. Size: 32mm X22mm X30mm length * width * height; The main chip: LM393, MQ-x gas sensing probe; Working voltage: DC 5V; With signal output indicator light; The dual signal output (analog output and TTL output) The analog output and increased with the increase of concentration, the higher the concentration higher voltage; Has a very high sensitivity to sulfide, benzene vapor, smoke and other harmful gases; With a long service life and reliable stability; Quick response and recovery characteristics; With mounting holes, easy mounting; The probe can be plug design, convenient test.