900mm F8.0 Super Telephoto Mirror Lens with Adapter Ring Fit for Olympus M4/3 Mount Camera Item Type: Camera Lens Material: Alloy + optical glass Color: As Pictures Shown  Weight: Approx. 1032g/36.4ozFocal length: 900 mm Aperture: F8 Mount: for M4/3 mount Applicable model: for Olympus M4/3 Mount Camera Optical structure: 8 groups of 8pcs Perspective: 3 ° Coating: multi-layer MC coating Front filter size: 105mm/4.1in Focus mode: manual focus Anti-shake function: none Closest focusing distance: 3.5m Applicable scene: landscape, architecture, characters, insects, tourism, business, sports, wedding, humanities, etc How e： 1. Align the identification point of the lens mount with the identification point of the adapter ring, and rotate it clockwise. When you hear a "click" sound, it means that the lens has been installed in place 2. Align the identification point on the lens adapter ring with the adapter ring to the identification point on the fuselage, and rotate clockwise when you hear a "click" sound, it means it is installed in place 3. Press and hold the camera lens release button and rotate it counterclockwise to remove the lens together with the adapter ring 4. Install the adapter ring release button and rotate it counterclockwise, the adapter ring can be removed from the lens