It's the type of bracket on a pivoting arm that allows you to swing the TV out from the wall. The bracket is supposed to take up to 40 kgs in weight. I weighed my TV and it was 37 kgs including its weighted stand - so, with the TV on the bracket, and the stand removed, the TV would weigh far less than 40 kgs. When attached to the bracket, the TV can tilt in the vertical plane, presumably for situations where you have the TV quite high and want to tilt it down towards the viewer. The problem is that the tilting mechanism is secured by two hand operated chunky plastic butterfly nuts, and with our heavy TV, even though I used a pair of pliers to tighten the butterfly nuts, the nuts do not grip sufficiently tightly and the TV tilts slightly into the room. What I need is to be able to fix the TV such that the screen is perfectly parallel to the wall, but this is very difficult to achieve. The tilting mechanism needs to be re-engineered to make it easier to fix the TV into a perfectly parallel configuration.