Model UP-4 incorporates a special concept of the unipivot principle. The bearing consist of a hardened steel pivot resting in a concave, polished sapphire. The bearing is damped in all directions with silicone fluid. The low positioning of the bearing provides for a greater stability compared to other unipivot arms, since a considerable part of the moveable mass of the arm is positioned above the pivot point.
With the model UP-4 the azimuth adjustment is made by the way of the counterweights.
The armtube plating being made without the use of magnetic materials.