With multi-layer, adhesive technology, iReliev(R) electrode pads provide optimal bonding to the skin, for a more comfortable and effective electrotherapy experience. The pads are compatible with the PlayMakar(R) Wireless, Model ET-5050. Stimulate and Relieve Uncompromising Adhesion, Performance & Longevity A More Comfortable Electrotherapy Experience Flexible Fabric Layer Contours Better to Your Body Free From Natural Latex Additional Details 3" x 5" Oval Series 4 Single Electrodes Refill Kit Contains Quantity of 4 Snap-Style Pads Compatible with the PlayMakar(R) Wireless TENS Unit + EMS Wearable Therapy System For Pain Relief and Muscle Conditioning, style# ET-5050