All Profoto Softboxes have a recessed front that allows you to attach a softgrid. The Profoto Softgrid 4 Feet Octa reduces the light spread to 50-degree. In other words, it creates a more directed light and eliminates a large amount of spill light, allowing you to shape the light with even more precision. By limiting the spread of light, a softgrid can help to create more contrast in your images, resulting in a more dramatic and moodier look. With regard to reducing unwanted spill light, it is especially useful when you need to avoid illuminating the background or surrounding areas.