Thank you for viewing. This is the Optart rear converter/extender HRRC-1.3X. It's a high-precision extender made by Optart that, when attached to a C-mount lens, magnifies the focal length by approximately 1.3 times. It's a very useful item for adjusting the angle of view in industrial applications, video production, CCTV/machine vision applications, and for those who want to extend the focal length of their existing lenses. The new retail price is around ¥36,575, making it a high-end accessory, but it's rare to find it used. While there are signs of use such as scratches on the exterior (see photos for details), the optics are in good condition, and there are no problems with the functionality itself. If you are considering reusing old lenses, repurposing them for special photography/industrial applications, or as an "extension tool" for situations where the angle of view is insufficient in video or experiments, please consider this item. #Optart #HRRC #RearConverter #CMount #Telecentric #LensAccessories #Lens #VideoEquipment #IndustrialLens #OldLens #CineLens #CinemaCamera #bmpcc #bmpcc4k #lumix #olympus #cooke #angenieux #kodak #bolex #kern #switar