1. High-definition display: large display screen LED display, clear handwriting, convenient and fast reading. 2. rotary switch: change control is simple and convenient, fine workmanship field precision pause and a strong sense. 3. Battery compartment: install 9V battery, easy to replace 4. Over-current protection: automatic recovery overload protection circuit design, not afraid of burning meter 5. Pen-shape meter: soft pen-shape meter, using compact soft rubber protective sleeve, anti-slip design, feel more comfortable. 6. Jack: Pen-shape meter Jack is smooth and solid, and the dial plug is good.