Fotasy GBB Flexible Gearbelt for 15mm Rod Rig Follow Focus with Premier Cleaning Cloth (Black)
The flexible gear belt can be used with any zoom or prime lenses with a wide range of lens diameters (any size from 46 to 110mm)" With Build in Aperture control, It is a solution of using Canon EF lenses to adjust aperture in other cameras with external aperture ring.