UNIVERSAL COMPATIBILITY: The ReaJoy tens unit replacement pads are Snap for Tens Unit with Standard 3.5 mm Snap-on connector, compatible with all muscle stimulators of most brand on the market. If you are not sure, please contact us before purchasing. EXCELLENT SELF-ADHESIVENESS: Our 2×2” tens unit replacement pads can be reused by Electrode Life Extension Gel. (Recommend brand: ReaJoy). It made of medical grade material, non-woven backing with black carbon conductor and premium gel adhesive. 40-PIECE SET: The pack of 40 TENS/EMS electrodes helps you get the most out of your TENS unit or EMS. And the resealable packaging prolongs the lifespan of TENS machine pads. Flexibly conforms to various body parts, effectively pain relief for arms, ankles, backs, legs, feet, elbow, hip, thigh, wrist or flat areas elbow, hip, thigh, wrist or flat areas. PREMIUM QUALITY: Made of high quality material so that you won't face risks during use. We're always looking to bring better health to our customers! Getting relief from muscle stimulators is safer, and can further protect you from harmful additives and consumption of prescription medication. 100% SATISFACTION: We have always been paying attention to improve the quality of our products. Pls feel free to contact us at any time if you have any dissatisfaction of this product. We are always here to solve your problems.