Rotalux softboxes feature double diffusion for super soft lighting. Use the Rotagrids with the inner diffuser only for a more dramatic look. The diffuser offers Velcro on the outer black frame, to hold a Rotagrid in place. This is particularly useful when using a grid on a bigger Rotalux and makes the Rotagrid more secure on the softbox, when an external diffuser is required for additional diffusion.