BELLOWS AND WOOD ONLY. The grinder is not included. If you’d like to customize the wood, feel free to email us at service@coweetwares.com The Niche Duo is designed for zero retention, although retention may vary depending on the climate and humidity. The bellows provide a strong enhancement, offering both aesthetic and functional benefits. It fits securely on the grinder and remains in place even when pressed vigorously. The 3D-printed gadget bypasses the lid switch and controls the grinder using only the on/off switch. It does not affect the daily use of the grinder. Simply remove the original plastic lid and use the original screw to secure the gadget. Benefits: The upper lid is removable, allowing you to feed beans directly from the opening. This process dramatically shortens the workflow, eliminating the need to repeatedly open and close the lid to blow out retention after grinding. Grounds can be blown out while the grinder is running, enhancing the blowing effects. The grinder can be running before feeding the beans, which is beneficial for the longevity of the grinder motor and burrs. The wood pieces (one above and one below the bellows) are handcrafted from quality Walnut or White Oak. They are carefully sanded and finished with high-quality, food-grade wax oil. The bellows are made from food-grade silicone, ensuring longevity and durability.