This particular lens comes with an Olympus/Panasonic Micro 4:3 mount. The aperture on the lens ranges from ƒ/22 to ƒ/1.8.
From London Camera Exchange
Olympus M.ZUIKO DIGITAL 25mm F1.8 Lens - Black
HDEW Cameras
Olympus M.ZUIKO DIGITAL 25mm F1.8 (Silver)
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