http://tinyurl.com/lb2jl4x
Opteka 500mm f/6.3 HD Telephoto Mirror Lens for Olympus PEN E-PL7, E-P5, E-PL5, E-PM2, E-P1, E-P2, E-PL1, E-PL1s, E-PL2 and other Micro Four Thirds Mirrorless Digital Cameras
High-index / low-dispersion optical glass, fully multi-coated, every element, anti-reflection coating
7 lens elements in 6 groups
Incredibly compact and lightweight
Great for the wildlife or nature photographer who wants to be hidden while taking photos of the subject
May be combined with the Opteka 2x multiplier for 1000mm (Sold separately - 47st Photo Item Code: B000JSZ41S)