Strong Velcro.

The most recent lasted from November until April when the velcro stopped working

I may write to the manufacturer about it, because I love the product, but for the price they could really use some better velcro

the material is soft and the Velcro holds well

While the velcro cannot be refreshed, the armband can be adjusted so the hooks connect to a fresh patch of loops

The material is separating and the Velcro has become less catchy over time

Like many other negative reviews, the velcro on the arm band separated after less than 2 months of use (and not that often - once or twice a week)

What I don't like is that the velcro wore out very quickly which was annoying to me because it was very expensive.

the Velcro is much better than other armbands)

It's just the flimsy velcro