Malcom Distributors WHITE 2.5mm Female to 3.5mm Male 3 rings Jack Stereo Adapter On/Off enabled - Convert 2.5 mm Stereo Cell Phone Headset to 3.5 mm MP3 Stereo Earpiece Earphones Input Jack for iPhone 1G 3G 3Gs iPhone 4, Blackberry, Motorola Droid, Palm Pixi, HTC Eris Nexus One, Samsung Galaxy S 2.5mm (3/32 inch) female to Smartphone 3.5mm (1/8 inch) male. End to end is 5 inches long. For use with 3.5mm plug on iPhone 3G/3GS, Blackberry Curve/Storm/Bold, Motorola Droid, Palm Pre, Palm Pixi, Samsung Galxy S Devices. Phone Headset to iPhone/Blackberry/Smartphone Adapter. Reduce Electromagnetic Radiation (EMR) caused by cell phones and bluetooth headsets. Stereo-channel enabled if your 2.5mm headset is stereo enabled too.