The XTB interface from JV Digital Engineering is a direct replacement for the CM11a which is no longer made. If you’re looking for a replacement or a new X10 interface this is a fantastic device. It implements the entire protocol of the original CM11a so you can connect it in exactly the same way to the same software, including XTension. The output level is far superior to the CM11 and it may overcome many reception problems you might have had with the CM11a in the same environment. The XTB-232 is our pick for the best X10 interface currently in production from anyone.