The Niche Flow Control Disc is a simple after-market installation for first generation Niche Zero grinders. Please note that current Niche Zero models come with the Niche Flow Control Disc pre-installed. The small (40mm), clear disc is made from food grade polycarbonate. When installed into the bean funnel, the Niche Flow Control Disc prevents 'pop-corning' - coffee beans jumping around the funnel prior to being fully fed into the burrs. Because the Niche Flow Control Disc feeds beans into the burrs at a steady pace the grind consistency is also improved. Click here to see how easy it is to install the Niche Flow Control Disc. One disc per order.