NWT Adjustable Speeds: Can choose different speeds based on which muscle groups you are massaging. Replaceable Massage Heads: Used on different body parts and muscle groups, relieves leg, back, neck, and shoulder muscle tension. Long Battery Life: 1800mAh rechargeable lithium battery can last up to 3-6 hours after fully charged for 3 hours. Quiet and Comfortable: High-torque motor goes as low as 35dB and maxes out at 45dB for in-home and on-the-go convenience. Easy to Carry: Mini size massage gun, It's also easy to carry all your accessories in a compact box. H1