The invention relates to a soft handle, which includes a soft shell, a special shaft, a connector, a joint, and an upper and a lower cap. The device includes an electric signal generator and an analyzer for analyzing the signal transmitted by the generator and signals reflected by the structure and signals transmitted by the structure. A ball screw groove of the nut member is having a loaded surface which is pressed against the balls, on the side of its groove base in the second axial direction. The high capacitance of the structure is due to the thin high k dielectric material used to form the etch-stopcapacitor dielectric layer 60. The invention is also directed to compositions containing and uses of the compounds of formula I. In some embodiments, an attachment point is provided at the rear of the platform so as to allow attachment to the front of a second platform, thereby forming a chain of platforms that can be towed as a group.