SK3665 is a type of RCA connector that has a black outer (insulating) jacket and nickel plated terminals. The jacket is 5.5mm wide, while the nickel-plated terminals are 4.5mm in diameter and 4mm in height. The terminals have a relatively flat exposed surface with a rounded-edge insulator, and can hold up to three round-pin audio or video cables inside the jacket. The terminals are designed to ensure a snug, interference-free fit with the cables.