CESS 3.5mm Male to 2.5mm Female Stereo Balanced Adapter Connectors - 3.5mm Stereo Male to 2.5mm Female(2 Pack) 3. 5mm Stereo Plug (male) to 2. 5mm Stereo Jack (female) Adapter Can be use 2.5mm Stereo Plug Work to 3.5mm Stereo Jack & Socket Fit smartphone headsets however it will not support the speaker or mic functions on the headset It is a reliable and efficient product for you Nickel plated for maximum signal transfer & durability.Material :Alloy