Lens Type: Circular fisheye lens</br>Lens structure:5 groups and 6 slices</br>Aperture range:F2.0-22</br></br>Product Description</br></br><b>Feature<b><br>Focal range:6.5mm Lens diameter:61mmLength:51.5mm <b>Weight:300g <b>Coating:nano-technology multi-layer coatingFull-frame Visual angle:diagonal 190° horizontal 190° vertical 190°APS-C Visual angle:diagonal 190° horizontal 190° vertical 190°</br><br/>http://www.amazon.com/gp/product/B01N3XKM9S