A 1/4 inch jack, also known as a 6.35 mm jack, is a type of audio connector commonly used in various audio equipment. It is often found on electric guitars, amplifiers, and professional audio devices. The size refers to the diameter of the plug, which allows for a secure connection and reliable audio transmission. These jacks come in two main types: mono and stereo. Mono jacks carry a single audio signal, while stereo jacks can transmit two signals, allowing for left and right audio channels. The 1/4 inch jack is favored for its durability and ease of use in both live performances and studio settings.