The Westcott Umbrella 4634 has a size of 213cm measured across the bow of the umbrella and is suitable for use with any studio flash kit. The umbrella has a diameter of 180cm. When using an umbrella the light gets a little harder than when using a softbox, but the light is softer than when pointing the torch directly at the subject. An umbrella is especially ideal to prevent hard shadow lines, in situations where multiple light sources are present and you use one or more umbrellas as fill-in flash.