Model Number: Instant Heat Pack-r42F Brand Name: J, J-jiaxing Key Specifications/Special Features: Instant heat pack (reusable)Can be used as cold pack after refrigerationActivate: bend metal disc, pack become crystallized and heated re-usable: submerse in boiling water for 5 minutes till crystal changed into liquidCool it then reuse againSize: 3 1/8 x 2 1/4 x 1/4 inchesColors: yellow or otherApplications: health and medicalVarious heat packs are availableCustomized colors and designs are accepted, such as printing your logo for promotionsPacking: inner 1 piece/carton