Rack-Mount PDU 6-15-F All lines are protected. Unit provides surge protection on all three modes (L-N, L-G, and N-G). Unit also has thermal protection on all three lines. 600V UL1449 Voltage Protection Rating (VPR). Outstanding protection against harmful surges. EMI /RFI noise reduction. Protect against data disruption due to electromagnetic or radio frequency interference. Standard 1" center-to-center spacing between receptacles. Space saving. Rack mount unit fits standard 19" Server Racks and Relay Racks with compact 1U design that takes up minimum space.