New since Mar. 23rd 2011:

Snap in bushings for insulated mounting of 4mm, 6mm or 8mm element rods through the boom

The example shows 4-mm-aluminium-welding rods through 3,2-mm-bushings. When using this method with mounting through a conducting boom (round or square) add the following lengths to each element (reflector and directors):

15-mm Boom: 1,5 mm for 144 MHz, 3 mm for 432 MHz
20-mm-Boom: 2,5 mm for 144 MHz, 5 mm for 432 MHz