OrthoTrode 2" x 2" Square Foam TENS Electrodes, Re-usable, CASE (4/Pack, 10pk/cs). Orthoco's OrthoTrode foam-backed TENS electrodes are stickier than previous versions and were designed for multiple uses. This is a foam-backed electrode and can be used under moist heat packs. Each pack is resealable. These are "excellent" electrodes for the price. *International Shipping Available.