A model is for USB charging, and B model is for battery. Please consider carefully before placing your order 3 in 1: The 3 massage heads of the acupuncture pen include scraping type, sphere type, node type, , with different massage heads and different massage methods to massage the body parts more effectively. 9 Power Levels: The acupuncture pen has 9 different levels to use depending on the muscle treatment needed. level 1 is the weakest and level 9 is the strongest, adjustable intensity for personalized treatment to get the best out of the acupuncture points. Effective Pain Relief: Use this massage pen regularly to relieve pain, relax and enhance a pleasant mood. Simply press the pen at your face to massage the surrounding skin and change the condition of your skin, making you look younger and fresher. Portable and Easy: The rechargeable acupuncture pen is small and portable to carry around with you, while simple to operate, you can put it on your body parts anytime and anywhere to massage your muscles and relieve pain. Exquisite Gift: The electronic acupuncture pen set is beautifully packaged, safe and effective, and fully functional, perfect for family and friends on birthdays, anniversaries, Valentine's Day, New Year's Day and Christmas. Size; 18.3 * 2.5cm, packaged in a box