Sony offers the MZ-R90 - the world's smallest and lightest Recording MD Walkman that combines the superb sound reproduction quality of digital technology with the ease and convenience of MiniDisc recording, in a unit less than an inch thick and virtually as small as a MiniDisc itself. Magnesium Top Cover is rugged, durable, and ultra lightweight and is designed for your carrying convenience. This MD Walkman provides world's longest playback and recording time of up to 14.5 hours Record and 29 hours Playback with 1 Sony "AA" Alkaline battery and Sony NH-14WM Rechargeable battery. It features Jog Lever for Convenient Editing Operation that lets you move quickly through tracks and other available functions with the press of the jog lever, then select desired track or operation with just another press of the lever.