RAK/BigRAK: Applicable for easy constructions as for example yagis or heavy short wave antennas. RAU: for smaller antenna system for VHF or shortwave. Mechanical parts consists of worm gear with worm and wormwheel, made from steel (as shown on the picture), guaranteeing long, continuous work and high reliability. The advantage is the possibility of alignment of worm and wormwheel holding down, what makes possible to eliminate side play in driving gear, which can appears after long usage time. The surface is painted with anti-corrosion paint.