DC Power Connector Plug Tip for Apple Laptops
One end of this connector tip is a 9.0 x 3.5mm male plug. The other end is a 5.5 x 2.5mm female jack

Connector size: 9.0mm (Outside Diameter) x 3.5mm (Inside Diameter)
Connector Tip Length: 16.5 mm

9.0 x 3.5mm male connector fits
Part of compatibility models:

Apple

PowerBook 1400 Series, PowerBook 2300 Series,
PowerBook Duo 2300 Series, PowerBook 3400 Series

PowerBook FireWire Series (M7712LL/A), PowerBook G3 14" M5343,
PowerBook G3 Series (1997 Models), PowerBook G3 Series (1998 Models),
PowerBook G3 Series (1999 Models), PowerBook G3 Series (2000 Models),
PowerBook G3 Series (Bronze Keyboard), PowerBook G3 Series (Early Original G3 Model),   
PowerBook G3 Series (FireWire), PowerBook G3 Series (Lombard),
PowerBook G3 Series (Lumbard), PowerBook G3 Series (Pismo),
PowerBook G3 Series (Wall Street)       

iBook Blueberry Series, iBook Clamshell, iBook FireWire Series,
iBook Graphite Series, iBook Indigo Series, iBook Lime Green Series,
iBook Tangerine Series