you could also create your own solution with a little bit of coding skills. RUT Routers allow it to switch SIM cards through a lot of functions. You could switch SIM by sending an SMS automatically from another application or you could just use the modbus protocol. Just take a look at https://wiki.teltonika.lt/view/RUT950_SMS_Utilities#Force_SIM_switch
or at https://wiki.teltonika.lt/view/RUT950_Modbus#Set_Parameters
Hope that helps! Happy networking!