This is a surge protective device for securing transceivers against over-voltage and surge current induced by bolts of lightning.
For the purpose of protecting the indoor equipment and circuitry connected to the LoRa gateway, you need to install an Ethernet Port Surge Protection Device (SPD).
RAKwireless recommends installing a lightning arrestor on all N-type antenna terminals including LoRa, LTE, and 2.4G Wi-Fi antennas. Please refer to the technical manual for wire type and gauge recommendations.