Surge Protection Device PanelNominal Discharge Current 10/20 kA Voltage 277/480 Phase 3YMax. Surge Current Per Phase 100kAMax. Continuing Operating Voltage 320 Voltage Protection Rating 1500V (L-N) 2500V (L-G) 1200V (N-G). 2500V (L-L)Modes of Protection 4 Mounting Style Surface or Flush Material of Construction MetalNoise Reduction Rating NRR -20dB to -40dB (50KHz-10MHz)Length 14.9 In. Width 10.31 In. Depth 5 In. Standards UL1449 3rd Ed.Includes Flushmount Collar