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
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

Product DescriptionConverts your 2.5mm stereo headset to a 3.5mm jack stereo headset. If your 2.5mm headset is on/off enabled so will the jack converted ones.
This adapter will work with the following phones:
iPhone first generation, 3G, 3GS
Blackberry: BlackBerry Bold 9000, Bold 9700, Curve 8900/ 8330/ 8320/ 8310/ 8300, Pearl Flip 8220 / 8230 / 8130 / 8120 / 8110, Storm 9530 / 9500 / 9550 / 9520, Tour 9630
Palm Pre, Treo Pro, Pixi
HTC Imagio / XV6975, Hero – CDMA, Touch Pro 2… More >>
Malcom Distributors 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, Blackberry, Motorola Droid, Palm Pixi, HTC Eris …