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 Professional Design: This tool is specifically engineered for creating central grooves, front arc grooves, and back arc grooves on half-rim or rimless eyewear.