Surge protective devices (SPD) protect equipment from abnormal voltage caused by lightning.
R5K
SPD for communication/signal/telephone line.- Two electrode ceramic tube
R5K3
SPD for communication/signal/telephone line- Three electrode ceramic tube
RHCA3216
SPD for communication/signal/telephone line- Chip surge absorber
RHCA4532
SPD for communication/signal/telephone line- Chip surge absorber
RHCA5039/RHCA5639
SPD for AC power supplies- Chip surge absorber