Nich Duo is built for zero retention while the retention could be higher or lower depending on the climate and humidity. Our bellows is a strong enhancement to your grinder providing both aesthetic and functional pleasures. It sits securely and tightly on the grinder and won't slip even being vigorously pressed.

The lids (one above and one underneath the bellows) are handcrafted from quality American black walnut, carefully sanded, and finished with quality food grade wax oil from Japan. The bellows are made with FDA-approved food-grade silicone to ensure longevity and durability.