A 4-pole jack connector, also known as a TRRS (Tip-Ring-Ring-Sleeve) connector, is a type of audio connector commonly used on smartphones, laptops, and other devices for connecting headphones, microphones, and other audio equipment. The 4-pole jack has four separate contact points on the plug that correspond to four different functions: the tip (T), first ring (R1), second ring (R2), and sleeve (S). The tip is usually used for the left audio channel, the first ring for the right audio channel, the second ring for the microphone input, and the sleeve is the ground. This type of jack allows for both audio output and microphone input to be transmitted through a single connector, making it a more compact and convenient solution for mobile devices. It is also commonly used in gaming headsets, where the microphone input and headphone output are combined into a single cable.