· [What's It Used For] - Used to connect 2 sets of BLUETTI AC500&B300S power stations with the main panel to build up a home backup system in rated capacity/voltage/power up to 12288Wh / 240V / 10000W.· [24/7 UPS Home Backup] - Tie the AC500&B300S power system to your home grid to power your home whenever a blackout occurs. Only a licensed electrician can install the UPS power system.· [Compatible Version] - It only works with 100-120V US plug version.· [Charging Tip] - This power system can be charged via solar panels or 50A split-phase AC cable or both simultaneously. AC input is only through the 50A split-phase AC cable but not the standard AC.· [What You Get] - 1 × 50A outlet box (Reliance), 1 × sub-panel (Included a 50A inlet SS2-50), 1 × 50A split-phase AC charging cable, 1 × NEMA14-50 to SS2-50R cable, 1 × communication cable.