The OMTs (OrthoMode Transducers) are passive components of front-ends of radio receivers, used in radio astronomy to separate orthogonal components in linear polarization of the electromagnetic signal coming from the celestial body under observation.
In the image, there are the OMTs of the new 100Ghz Multifeed. OMTs are produced using the platelet technology by CNC mechanical manufacturing with high speed milling and wire electrical discharge machining. The average precision of this kind of production is to within a hundredth of a millimeter both as for dimension and geometries.