airport card

Even the latest Power Mac G4 model (released in 2003) used the "original" AirPort Card. There were two versions of this card, but I have to second Jan Hedlund's suggestion to go with an external solution. Either with the suggestion provided or an external USB wireless adapter.

There are, at least, three reasons why you will not want to go with the card:

1. As Jan has mentioned, it would be limited to the 802.11b standard. Adding this device to current Wi-Fi networks is still possible, but will cause overall performance issues as that network would have to "slow down" to allow your G4 to communicate on it.
2. Wireless security would be very limited. Depending on which version of AirPort Card you get, you would only be able to use WEP or WPA security types. Both are considered non-secure these days.
3. Finding a "new" card will be difficult and getting a used one will be iffy, at best.

Hi,

Instead of using an AirPort card (802.11b), a better idea may be to connect a Wi-Fi range extender operating in a wireless Ethernet bridge mode (also known as client or media adapter mode) to the Ethernet port of the computer. Models with wireless Ethernet bridge capabilities include Edimax EW-7438RPn Mini and TP-Link RE200, just as two examples.

It might also be a good idea to post your question in the support forum for the G4, which is linked below:

https://discussions.apple.com/community/desktop_computers/power_mac

We handle questions about the AirPort routers in this support forum......the AirPort Express, AirPort Extreme and AirPort Time Capsule, the products that you see below......although it is always possible that a user here might have the info that you need.