I have 2 VERY fluffy very large white dogs that shed all the time. I probably go through these belts more often than I should, but then again - big dogs that shed all the time. So as soon as I smell that burnt rubber smell, I know my poor vacuum has given in to the onslaught of fur and it's time to put in a new belt. Then it's like a brand new car! They arrive on time and at reasonable prices even when I go through them (1 new belt every two months).