This block is for use where the Centrex is to be mounted on the back of the fence structure. The purpose of this block is to give adequate operating height. It is important to ensure that the section of the fence onto which the Centrex is to be mounted is sufficiently large and rigid to prevent flexing. Large and rigid to it may be necessary to consider the alternate systems of mounting on pages 80 to 89. The basic cross section of the mounting block giving the sizes in mm. The ideal mounting position on the fence for stability and rigidity. Spacer block 500 mm to be cut into desired length by the user