Professional Design: This tool is specifically engineered for creating central grooves, front arc grooves, and back arc grooves on half-rim or rimless eyewear. Low Vibration Operation: The design allows for a comfortable grip during use, ensuring stable placement that is ideal for precise tasks. Adjustable Functionality: This manual tool allows for customizable grinding with seven selectable groove depths ranging from 0 to 7mm. Durable Construction: This machine is built to last, maintaining its original color and integrity over time. Its panel groove design accommodates long lenses Service:We attach great importance to our customers' shopping experience. If you have any questions, please feel free to contact us, we will reply you as soon as possible within 24 hours