To activate, just open the pack.All natural ingredients heat up when they contact Oxygen.Seal from Oxygen in zip-loc bag and reuse the next dayManufacturer: Ergodyne. Place of Business: SAINT PAUL, MN, 55108 US. Part Number: 16991. Product Dimensions: 24.13 x 17.78 x 13.97 cm; 2.72 kg. Item model number: 6990. Power Source: Disposable Air-Activated. Item Package Quantity: 1. Batteries Required?: No. Item Weight: 2.72 kg. Country of origin: China. ASIN: B000LE8X9K. Customer Reviews: 5.0 5.0 out of 5 stars 7 ratings 5.0 out of 5 stars. Best Sellers Rank: #236,469 in Health & Personal Care (See Top 100 in Health & Personal Care)#1,226 in Heating Pads. Date First Available: Aug. 10 2018.
