I dropped the vial of insulin, but only saw a dent in the metal ring. However, my cat's glucose started to rise rapidly, when it was thought he was in remission. After 2 glucoses in the high 400's, my vet asked if I could replace the vial, because dropping the vial can cause problems with the insulin itself. Though it's very expensive, I knew this was my only option. Ordered it late on Friday afternoon, on line. The office was already closed. I had it Tuesday afternoon! His latest sugar was 169! Thanks for the speedy service!