Instant hot pack (hand warmer) material: 0.3mmPVC 1) Use for the first time: a) A hand kneads the bag body, the thumb and index fingers of another hand take hold of the slice inside bag, pressing the bottom for several times, the liquid inside the bag will start change into the solid to erupt the heat immediately b) When the liquid is changing into the solid, you can press the bag body lightly to make calories even and to make temperature even c) Then you can put the bag on or in the place where need it 2) Use for the second time: a) Keep warm or hot applying for 60 - 120 minutes, the bag body becomes gradually cool, if you want to use again, please put the bag in wrap into the boiling water heats about 5 - 7 minutes, making all the solid inside the bag become liquid b) When the bag becomes cool again, you can use it according to the first-time operation method to get warm c) According to the above-mentioned operation method, this product can continue to use again and again, which is the ideal warmer Regulations: 1) Prevent the products from sharp stabs and heavy pressure 2) Don't press the slice again when the bag making fever 3) Please use the product after doctor's guiding Packing: OPP bag with instruction, color box PVC box or OEM