This simple-to-install add-on accessory allows you to integrate MantelMount seamlessly into a custom-built wall opening. Easily fitting between standard or custom stud configurations, the RB100 provides the flushest TV-to-wall storage on the market by allowing the MantelMount center arm to now fold into the wall opening when the TV is in the raised position. The result is concealed mounting hardware and a 1.8 inch flush-to wall TV storage! (For Models MM700, MM540 and MM340)