The Ericsson Cradlepoint RX20-MC is the expansion accessory for fleets and field deployments that run the R920 ruggedized router and need more than one carrier path or a connection to serial equipment. It docks to the R920 and adds an MC400 modular modem expansion slot. An MC400 LTE or 5G modem, sold separately, then provides a second cellular link for dual-carrier connectivity. It also adds a DB9 RS-232 serial port and a 6-pin GPIO connector (2x3 Molex Micro-Fit). The accessory has no separate power input because it draws power from the host router. With an MC400-5GB modem installed, the R920 and RX20 together draw 15 W at idle, 19.3 W typical and 23 W under heavy load at 12 V input. The housing is IP64 rated as dust tight and protected against splashing water. It operates from -30 °C to 70 °C and meets MIL STD 810G and SAE J1455 for shock, vibration and humidity. The calculated MTBF is 7,814,449 hours (Telcordia SR332 at 25 °C). Certifications include UL/cUL, CB Scheme, EN 62368-1, E-Mark for vehicles and EN 55032/55035 for EMC, along with WEEE, RoHS, REACH and California Prop 65 substance compliance. Activation and use require an R920 licensed to an Ericsson NetCloud Service plan. Cradlepoint hardware carries a limited lifetime warranty for as long as it holds an active NetCloud Service subscription. The box includes the RX20 managed accessory, a small accessories kit and a mounting template. A data sheet is available for this product.