Precise Lighting with Less Spillage: The softgrid creates a more directed light and eliminates a large amount of spill light, allowing you to shape the light with even more precision Compatibility: It is important to note that it is only to be used with Profoto flashes with LED modeling lights. It must not be used with Profoto flashes with halogen modeling light due to its heat resistance Reduction of Light Spread: The Profoto OCF Softgrid 50-Degree 3-Feet Octa limits the light spread from your OCF Softbox Octa. You can attach an optional Softgrid on your OCF Softbox to reduce the light spread to 50 degrees