1. The top of the probe head is smooth, not easy to wear the lens 2. Precise scale, clearly visible 3. Thread design, feel comfortable, non-slip and not easy to fall 4. It is suitable for 1.53 lens, cannot measure refractive index 5. Material: stainless steel 6. Scale: 0-20 degrees 7. Weight: about 118 grams 8. Dimensions: 50 x 60mm