3.5mm Male to 2.5mm Female Audio Adapter: 2.5mm to 3.5mm

3.5mm Male
to 2.5mm Female Audio Adapter converts a 2.5mm headphone/AUX plug to fit a
3.5mm audio port. Use it when your headset or AUX cable has a 2.5mm connector
but your phone, laptop, or speaker uses a 3.5mm jack. Simple, portable, and
easy to use.