Umbrellas generally provide a wide angle of light spread, particularly when used as bounce lighting. For the times when you want to minimize this spread, the adjustable models allow you to modify the light output by adjusting the umbrella's shape from round to square to rectangular. These subtle adjustments will change your highlight and coverage and allow you to fine tune your image. Adjustable frame with hot silver. A Duracloth exterior with a laminated silver interior. The adjustable frame allows you to shape the light coverage of your umbrella.The new and improved umbrella line includes ribs and strut pivots that are now made from a fiberglass composite, which is not only stronger, but also offers greater resiliency and durability than steel or aluminum. This new design feature allows for almost carefree handling, all but eliminating damage caused from over bending delicate steel tube ribs. All umbrella center poles are extruded and closed off at the base (vs. folded, hollow tubes, like many other umbrellas, that are easily bent and dented) adding to the durability of the Photoflex.