The Prosafe APS135W Power Module is for use with the GSM7328S-200 and GSM7352S-200 Gigabit L3 Managed Stackable Switches from Netgear (switches available separately). The rev 2 switch hardware features a removable power module as the switch's main power supply. In the event of a power supply failure, the switch is able to use an external RPS device for power (available separately) while the internal power module is replaced.