Power Supply, 450 W for the some models of PowerMac G5. To confirm if this is the correct replacement, you need to check your original power supply to see if it is a 450W unit. You can also check the EEE code which is the penultimate 3 characters of the serial number of the power supply (not the Mac). This is the correct power supply if the EEE code is NYJ, P28 or RQ5.