Here's what the Boostaroo personal audio amplifier/splitter will do for you:

• Allow you to share your player with up to three people with no loss of sound quality.
• Boost the iPod volume by up to 40%.
• Increases battery life by powering the headphones independently of the iPod

Technical specifications

Frequency Response: The Boostaroo employs similar output amplifiers to those found in CD players. Frequency response is equal to or exceeds specifications. Typical specifications are 20 to 20,000Hz +/- 2 dB (EIAJ CP-307 Method).

Output (@ 3VDC): Into 16 ohm head phones (stereo mini jack), approximately 40 mW per channel, 12 dB gain in sound per channel.

Product Dimensions:
Size: 4.5" x 1.5" x 1.1" 11.43cm x 3.81cm x 2.79cm)
Weight: 6 oz (170.10G) with 2 AA batteries.
Cord: 12 inches (30 cm)
Color: Clear (Translucent)

Requirements
• Connects via standard 3.5 mini Stereo jack.
• Requires 2 standard AA batteries (normal or rechargeable, batteries not included)