AUX Audio 2.5mm Female to 3.5mm Male Converter

From the shop's description

Features: This has a Male 3.5mm Plug and a Female 2.5mm Socket . They are commonly used with smartphones, tablets & modern laptop computers. The single 3.5mm plug with 3 Pole conductors is used for headsets that provide stereo sound. This adapter allows you to use headphones and audio cables Specifications: Male Connector 3.5mm (TRS) Phone Plug. Female Connector 2.5mm (TRS) Phone Socket. Color: Black. Nickel plated contacts Overall Length: 37.5mm(Approx) Male Connector: Length: 15mm Diameter: 3.5 Female connector: Diameter: 2.5mm