857-090. The Paxton Power Supply 857-090 is to suit the Net2 networked access control system. This model comes without housing, and must be used with a weatherproof casing if intended for use outside.. Tamper switch registers an alarm if the lid is opened while connected to an ACU or I/O board. ABS plastic construction. Not weatherproof - must be concealed within a waterproof housing if intended for use outside. To suit Paxton Net2