It is a 1/8 to 1/4 stereo cable.
This adapter allows you to connect devices like smartphones, tablets, iPods, and headphones with a standard 3.5mm port to audio devices that have a 6.35mm stereo port. For example, you can use it to connect a piano keyboard to a 3.5mm port, a guitar to a speaker, an amplifier to headphones, or even a pair of 6.35mm headphones to a computer. It's a versatile tool for connecting different audio devices with varying port sizes.
Product Name: 3.5 to 6.5 Audio Cable
Core Material: Enamelled Copper
Plug Material: Gold Plated
Shell Material: Alloy
Outer Cover Material: PVC
Usage: Connects mobile phones or computers to speakers, amplifiers or electric guitars.