Adding the E-Z Command Dynamis Pro Box to your Dynamis DCC system delivers more versatility to your railroad. The Dynamis Pro Box allows the use of three additional wireless controllers (maximum four), additional wireless receivers, and the use of programming tracks to read and write CV values. All of this plus a PC interface will transform your Dynamis DCC system into a Dynamis Pro system. Additional wireless controllers 36507 sold separately). Additional wireless receivers 36509 sold separately.