I have been using this product (the shoe lights) for years as a night runner. They are an essential item for running safely at night. It's disheartening when one light goes down - I feel unbalanced. Thankful I was able to get a right shoe replacement, so quickly. Prior to this purchase, I broke the blue clip - again, replacement part available for purchase and received quickly. As a runner, I don't leave home without these lights, when it's dark. Restock the pairs soonest, I think having a backup pair in my arsenal is necessary. Great product.