Aputure Barndoors / Grid / Gel Holder Kit ( For LS 120d/II & LS 300d/II ) are design allows for one to four of the leaves to be swung into the light's beam to illuminate areas that you want while keeping light from areas where you don't want it. The 30-degree grid narrows the beam spread. The barndoors also include a magnetic gel holder that allows filmmakers to easily add color to their lights' output.