This is a Smith-Victor 32BS 32" Black/Silver Umbrella. Umbrellas soften, broaden, and diminish the light output of any tungsten or flash light source. Umbrellas with a white interior will soften and weaken light more than an umbrella with a silver lining.
Choosing umbrella size is determined by the size of the subject, and the strength of the light supply being used. Choosing an umbrella surface is as subjective as choosing a paint and brush.
Silver Umbrella softens with a specular highlight.
This size is perfect for a 1 person head shot, or 3x4 ft product setup.