The WI-42-UBR-10H is a high-precision WR-42 H-Plane Sectoral Horn Antenna professionally engineered and manufactured by Fei Teng Wireless Technology Co., Ltd. (FT-RF) for specialized wide-vertical illumination environments. Operating within the high-frequency K-Band spectrum across the continuous 18.0 GHz to 26.5 GHz band, this premium antenna is expertly flared in the H-plane to deliver a distinct, highly predictable Fan-Beam radiation pattern profile (12° H-plane x 110° E-plane) combined with a calibrated nominal gain of 10 dBi. Featuring a Direct Waveguide Input interface with a standardized UG-419/U (UBR Style) flange mating face, it ensures flawless structural impedance coplanarity and ultra-low-loss power transfer, safely managing continuous wave power loads up to 500 Watts (CW). Precision CNC machined from high-grade structural aluminum alloy in Taiwan, it exhibits exceptional electromechanical longevity, an ultra-lightweight 45g profile, and excellent pattern isolation metrics combined with a maximum V.S.W.R threshold of 1.3 : 1. It stands as the definitive choice for broad-area environmental scanning, automated antenna characterization ranges, industrial EMI/EMC compliance validation scanning, next-generation satellite tracking networks, and mission-critical Signal Defense verification setups demanding uncompromised millimeter-wave performance parameters.