The RSH-20 kA SPD for X-13 / X-Style Motors is a surge protection device that protects single-phase 120/ 240V ECM indoor motors from transient over-voltage and natural-cause surges. Type 4CA Device - mounts between the motor and power harness. Max discharge current per phase – 20kA (1 hit survivability), nominal discharge current – 5kA (15 hits survivability). Features Thermally Fused MOV technology for safety & performance. 3 modes of protection: L-G, N-G, L-N. Plug-n-Play for ease of installation. Diagnostic LED indicates protection.