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  • Unbranded
  • 360 Degree Knurled Edge
  • 80mm Outer Diameter (O.D.)
  • 77mm Front Inside Thread / Compatible with any 77mm diameter filter
  • Made of solid billet aluminum and anodized black


The SIGNATURE SERIES Pro SimRing  screws onto the front filter thread of your lens and acts as a step up ring to provide a 77mm front internal thread for screw on accessories, while maintaining a consistent 80mm outer diameter for matte box compatibility.


Simply put, our 80mm Rings are designed for precision and optimum fit, smoothness, and compatibility with any matte box system on the market. Converting your front outer diameter to 80mm is a quick and inexpensive upgrade that adds purpose and convenience to any lens set up.


To select the size you need, you must determine the front filter diameter of your lens.  Please follow the resources below as a reference.




RESOURCES: (filter sizes, lens info)

Contax Zeiss Lenses

Leica R Lenses

Nikon Lenses

Canon FD Lenses

Mamiya Lenses

All Other Lenses


$35.00 Regular Price
$25.00Sale Price
    • 80mm Outer Diameter
    • 77mm Inside Thread / Can be used with any 77mm diameter filter
    • Made of solid billet aluminum and anodized black

***Please allow 3-5 business days for engraving***


Do you have a custom design or logo you'd like on your caps? Send it to with your order number in the subject line.


Special Instructions:

  • Requests to change lens information and data will not be accepted once an order is submitted for processing and engraving.

  • Please leave notes and instructions for EACH cap in the "Additional Info" Section. 

  • If you're sending us a custom design file, please let us know by selecting the corresponding options or simply indicate that in your instructions.

  • If you do not see your focal length or f.stop in the pull-down menu, DO NOT select the closest number.  Please leave the exact info in the "Additional Info"  Section

  • If you will be submitting a custom design file, please note that on the order.

  • For custom designs, please download this Illustrator TEMPLATE and export as a transparent (no background) PNG file.  Email the design file to with your order number in the subject line.


Watch Mark Holtze's video to learn more about the SIMMODING process: VINTAGE LENSES FOR VIDEO


Our Rear EF caps utilize a 1mm thick anodized aluminum top plate, allowing us to custom engrave to your specifications. Functional and stylish.


Want a matching Engraved Front Cap? Check them out here!


If you do not see a brand or focal length you are looking for, simply select OTHER and leave us a note.

Product Name


Options Title

Custom Text Field Question

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Please check all the fields above.
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