These are metal flaps that extend out past the light source to help control the light from spilling everywhere. You can spin them to deliver horizontal, vertical or diagonal light control patterns. Never fly barn doors on 18K’s or 20K’s, they become a sail very fast and are heavy and can fall out easily.
I wanted to continue my instruction on shaping light techniques with using specific theatrical lights. Hold on, how does a light shape itself? Well, the ETC Source 4 Leko light is like having a grip and flag package inside your light.