As the product name suggests , these are for the purpose of locking ear bud headphones firmly into your ears . I use these for running and exercise . This product gets 5 stars from me because the design is so simple and works so well . I have spent a good few hard earned pounds on sports related headphones in the past that fall out of your ears at the merest movement of your head , but lots of runs later and not a single fall out . Apparently this product does not fit all types of ear buds so I would have a good look at the product description photos and buy some ear buds similar to those . An unexpected plus with budloks is that because they hold your buds in place so well it seems to help with noise isolation even on the cheaper ear buds . There are 3 sizes of budloks in the package , I use the medium . The silicon they are made with seems quite strong so I am guessing they will last for ages . Just buy them .