Compex TENS/Heat Knee WrapCompression and Heat to Relax Muscles for Pain Relief. Compex TENS HEAT Knee Wrap The Compex TENS Heat Knee Wrap and Unit delivers comfort and patella knee support. The Compex TENS Heat Device in conjunction with the knee wrap offers eight modes to help temporarily relieve pain, whether from exercise, household work, work or day to day activities. The TENS function also aids in chronic pain management, intractable pain, and pain associated with