Ammeltz Yoko Yoko Adhesive Heat Patch provides up to 8 hours of non-medicinal heat therapy for neck and shoulder pain relief. Designed for single use, it offers soothing warmth to alleviate discomfort and promote relaxation. Ideal for those seeking targeted relief from muscle tension and stress. Features Air-Activated Warmer Up to 8 Hours Relief Non-medicinal Heat Therapy Thin & Discreet Adhesive Heat Patch Single Use Only Key Materials: Non woven fabric patch; Iron Powder, Activated Carbon, Water, Vermiculite, Salt (generate exothermic heat through oxidation).Kobayashi: Innovators in health and wellness solutions, offering effective relief for pain and discomfort.Apply To Clean, Dry Skin. Use Single Use Only.Single Use Only.