OM System DR-79 Decoration Ring for M.Zuiko ED 300mm F4.0 IS PRO

The 300mm F4.0 IS PRO is often used hand-held with the tripod mount removed to save weight, and that leaves the collar seat bare. The DR-79 is made specifically to match this lens and covers that section of barrel.

It matters more here than on shorter lenses because the exposed area falls exactly where the supporting hand sits under a long telephoto. With the ring fitted the barrel is continuous and the mounting surfaces stay protected between uses.