Quick Answer: The ByteX Stainless Steel Manual Coffee Grinder is a manual coffee grinder from ByteX designed for grinding coffee beans without electricity.Key Details Fit for Mason Jars: This Coffee Grinder Lid is specifically designed to fit all Regular Mouth Mason Jars. Premium Manual Crank Grinder: Enjoy the full control and fun of grinding your coffee beans manually while preserving the aroma and flavor of your beans with our efficient ceramic burr grinder. Durable and Rust Proof: Made from high-quality stainless steel and ceramic, this coffee grinder lid is built to last, resistant to rust, and ensures a consistent grind every time. Portable Coffee Solution: Perfect for coffee lovers on the go. Adjustable Instructions: Remove the gold nut, handle, and the round piece beneath it, then rotate the gear-shaped piece up or down the threaded rod to move the grinder pieces closer or farther apart.