The bracket length is adjustable from 10cm to 15,5cm. Using the clamp screw, you can obtain all intermediate sizes. Provided with a security lock, in case the regulating screw loosens, blocks the bracket at maximum extension. It's used to compensate for height differences in ceilings of 5,5cm or more, with combinations of other brackets. It's also used for obtaining intermediate sizes in combination with the extendable ceiling brackets.