Karl Stokes, Beijing Jesse Clock Club Technology. Karstos is a German medical instrument company, specializing in the production of endoscopes and related equipment. Its nose and skull base instruments include 2D and 3D endoscopes, surgical tools, high-speed motors and near-infrared fluorescence imaging systems. Beijing Jessie Zhonghui Technology Co., Ltd. is a China medical instrument company, specializing in the production of RF plasma surgical equipment and disposable cutter heads. The brands of nasal skull base instruments are Carl Stoss and Beijing Jesse Zhonghui Technology.