Tribest Corporation is a leading designer and manufacturer of a broad range of high quality small appliances for healthy lifestyles. Our products highlight leading technology and combine that with affordability to bring the best experience to everyone. We are innovative leaders in the Juice Extractor, Grain Mill, Blender and Sprouter business and we continue to bring the best products oriented towards the health and well being of our customers. GSE Outlet Adjusting Knob. Green Star Juice Extractor's are reputably the world's fnest juicers. With Green Star, you can easily add value and versatility by purchasing extra parts and accessories which allow you to expand your juicer's capabilities, and extend your juicer's life without interrupting your daily juicing regiment.