... Pack 1.Easy to use,can reach 43 C. long tiem hot-last about 40 minutes 2.Non-toxic,non-caustic.disposable ... -last about 40 minutes,2.Non-toxic,non-caustic.disposable.Use:1.Locate inner liquid pouch at the arrows ... .Shake to mix contents.Application:1.This instant hot pack can release heat within 5 seconds,conveniene to use ... a cold.(3) Dysmenorrhea,post partum abdomen recover. Disposable Instant Hot Pack