The world's lightest MD Walkman player, MZ-E900, is a mere 1/2" deep, weighs just 2.1 ounces, and slips easily and securely into jacket pocket or handbag for digital quality entertainment on the go, anywhere. Its full magnesium body employs an advanced manufacturing process to create ultra portability and high durability. MDLP Long Time Recording and Playback lets you record 2X (LP2) or 4X (LP4) longer on an 80-minute MiniDisc to provide as much as 320 minutes (over 5 hours) of music with excellent sound quality. Skip-Free G-Protection technology makes the MD Walkman an ideal on-the-go companion, with an advanced system that provides more than 10-times faster shock recovery compared to conventional systems, ensuring perfect playing performance without skipping even during such active uses as jogging. Up to 100 hours playback with rechargeable battery and 1 Sony "AA" alkaline battery (LP4 Mode) is a result of advanced Sony engineering, providing long battery life.