Noark Surge Protection / Protective Device (SPD), UL 1449, for type 4CA applications , U4 series, L-N / N-PE 20kA (8/20µs) UL nominal discharge current - 1-pole + neutral (1P+N) - 347Vac/600Vac voltage system (UL) rated voltage , MCOV (L-N) 550V maximum continuous operating voltage (Uc MCOV), DIN rail mounting (35mm width), equivalent to 1002734