Shorter cable can adapt a 2.4mm. stereo headset to be used with the folowing items: Features MP3 Player or PMP. Laptop Computer. Most other devices with 3.5mm. input jack. Longer cable allows you to play music from mobile phones wiht a 2.5mm. headset jack on - Car stereos home streos and portable audio systems with a 3.5mm auxiliary input jack. Item Weight - 0.25 lbs.