Tried this product again and it still doesn't work after the redesign. I bought the original pen and it lasts and they are second to none, wash after wash, stayed put no matter what. I took the second pack and about half failed after a few washes. Decided to try the new design and it didn't work after 1 wash. This product has gotten worse not better, you love your collar but this product falls short of expectations and its expensive treat fails after 1 use.