1. Use disposable cartridge needle.
2. Wireless use, can be used without Straight charging source.
3. After the battery electricity being used out , use the straight charge source add the electricity.
4. The battery can be working for 2- 3 hours.
5. Low voice and won't shake when drawing the straight line.
6.Adopt the technology of keeping constant output voltage,when the battery energy is going to run out of,the machine still keep a same (5.2V) output voltage.So the machine power won't get low when the battery energy gets low.
7.When the machine pen is out of energy,you can link it with the power adapter,and then continue to work.