Users of the Fitbit Charge 4 claim that they cannot wear the product because of a design defect that causes the band mount to break. Some customers have experienced broken bands as soon as four days after use. When the band breaks, the watch may fall off and end up lost. Fitbit has given customers replacement bands, but Fitbit refuses to continue replacing the band after the warranty has expired. One customer has received four different band replacements. Customers have reported the default on Fitbit Inspire and Versa 2 watches as well.