Your OP/TECH USA Fast Cap™ lens cover consists of three parts: plastic cap, camera ring and threaded adaptor ring.
To attach to the camera: 1. Take the entire assembly as packaged and screw it clockwise into your camera or filter as though it were another filter. (To first start, turn counter clockwise a quarter turn).
To adjust the position of the cap on the camera:
2. Open the cap and lift the camera ring near the hinge. (It may be necessary to tighten the threaded adaptor ring on to your camera once the camera ring is removed.) Rotate the cap to the desired position and replace the camera ring making sure the ridge on the adaptor ring snaps firmly into the groove in the camera ring.
To close: 3. Press firmly in the center of the cap to insure a tight seal. To remove: 4. close cap and unscrew as you would a filter.
For best results, annually lubricate the inside lid ring with a cotton swab and a light touch of silicone.