Monoprice 107121 2.5mm Mono Plug to 3.5mm Mono Jack Adaptor, Gold Plated (2 Pack) Save when you buy the 2-Pack! The connectors are gold plated to ensure a smooth corrosion-free connection Important: Although this adapter will physically connect a headset to a smartphone headset/microphone jack this will not allow use of the microphone This adapter has TS (Tip-Sleeve) connectors with two contact points while a headphone/mic device requires TRRS (Tip-Ring-Ring-Sleeve) connectors with four contact points