Keep your Sigma 300-600 f/4 DG OS protected and looking new in this Lens Cover from LensCoat/ Made from 100% closed-cell neoprene, it prevents scratches and damage due to minor impacts. Easy to install and remove, the cover slides on like a sleeve and has a grip interior to keep it in place. The clear plastic window maintains your view of the autofocus and IS controls. The cover acts as a thermal barrier between your hands and the lens in cold temperatures.