Monoprice 107125 3.5mm Stereo Plug to 2.5mm Mono Jack Adaptor, Gold Plated 3. 5mm Stereo Plug (male) to 2. 5mm Mono Jack (female) Adaptor - Gold Plated Will fit smartphone headsets however it will not support the speaker or mic functions on the headset. Item received may not match photo or specs shown It is a reliable and efficient product for you