Dual Therapy to Relax Knee: Combines targeted heat therapy and soothing vibration to relieve knee pain from arthritis, or post-workout soreness. Customize settings for gentle warmth with light massage or intense heat with deep tissue vibration to improve circulation and relax muscles Heat Therapy: The knee heat pad with massage has 3 adjustable heat levels (temperature range from 90 to 135°F), which is excellent for soothing stiff knees and accelerating blood circulation; With an overheat protection chip to ensure stable heating Vibrating Massage: It has 2 vibrating motors that deliver soothing massage to tissue muscles and help further relax sore muscles; Provides 3 adjustable massage modes; Automatic shutdown after 45 minutes of work to ensure safe use USB Powered for Enhanced Portability - Comes with an extra 4.9-foot USB cable that can be plugged into a USB adapter with 2A output or a power bank (not included) to work; It is not rechargeable and must always be plugged in when working Adjustable Straps & Keep in Place: Adjustable Velcro straps hold the knee massage heating pad in place, suitable for maximum thigh circumference up to 18.8 inches and maximum calf circumference up to 17.6 inches, can be used on most people's knee for both men and women Ergonomic Design for Secure, Custom Fit Adjustable straps and contoured shape provide a snug, non-slip fit for all knee sizes. The flexible structure allows natural movement while delivering concentrated heat and vibration to the knee joint and surrounding muscles.