This is a waterproof 4-pin front-lock male connector with M12 A-coding and PG9 thread. The corresponding opening size on the industrial equipment should be PG9 for proper fitting.

First of all, let's take a look at its 4-pin design. Compared with connectors with other numbers of pins, the 4-pin design has unique advantages. Compared with 2-pin connectors, the 4-pin one can carry more functions. 2-pin connectors usually can only achieve simple power transmission or single-signal transmission, while the 4-pin one can simultaneously complete transmissions such as power supply and two different signals, or achieve more complex functions like dual-power supply, which greatly increases the flexibility of device connection.

Compared with 3-pin connectors, the 4-pin one provides an additional pin, which makes it perform better in some scenarios that require precise control or transmission of multiple types of signals. For example, in some industrial sensor applications, a 3-pin connector may only meet the basic power supply and signal output requirements, but a 4-pin connector can integrate various functions such as power supply, signal output, and calibration signal transmission, thus enhancing the accuracy and adjustability of the sensor.