Olympus MC-14 1.4X Teleconverter for the M40-150mm and 300mm f4.0 PRO Lenses (Black) Special teleconverter for Olympus 40-150mm f/2.8 PRO lens Increases maximum focal length to 420mm equivalent.Accessories for zuiko digital lens / OM-Series lens:OM-D / PEN series, OM-series,Four Thirds series Preserves dust, splash and freezeproof properties of master lens Compatible with announced Olympus 300mm f4.0 PRO lens coming in 2015