The end cap fell off when I was about to get into my car. I was about to put my purse in the car and saw a blue blob on the ground. Then I looked at the slime timer in my hand and realized the end had just fallen off. Fortunately it did not hit the cream colored leather on my seats or it would have received negative numbers. The slime just sort of blooped from one end to the other...it did take a few minutes, but didn't look very timer-like.