The VAB plastic ferrules are designed to fix the HG / RG series nozzles and the ZBA threaded balls on the ZP and ZL series clamps. Their particular thread and shape allow them to assemble the cap by hand, with no need for tools, thus making all servicing operations easier and quicker. They are made of high-quality PP or chemically bonded fibreglass to maintain stability at high temperatures and offer the best chemical resistance.