These Clip-ons are fully rimmed with a bar on top and four prongs usually one in each corner. The simple "Top Bar" design makes it easy to mount while wearing your glasses as well as adapting to any frame. Using one of the colors in the "Color Chart" supplied these clip-ons can usually be custom made in 1-2 days. All these characteristics make these clip-ons the perfect choice for those who are always on the go without wanting to give up function and style.