Netgear prosafe modular power supply unit 150w ac aps150w is compatible with select managed switches such as m4300 28g gsm4328s and m4300 52g gsm4352s these m4300 series switches come with one psu pre installed these m4300 series switches come with one psu pre installed another aps150w in second psu bay can be combined for 11 power redundancy or 11 power expansion