The used Optitek Canon ProLock-i is a video lens adapter that lets you use Canon EF lenses with Sony FZ camcorders. Key features include:

Canon EF to Sony FZ. The Optitek Canon ProLock-i lets you use Canon EF lenses on Sony FZ camcorders, like the PMW-F5 CineAlta and PMW-F55 CineAlta 4K.

Electrical Contacts. Enables powered control over the iris in 1/3-stop increments via keys on the mount, as well as image stabilization and autofocus.

Power Drawn From Camera. Rather than requiring an additional power source, the ProLock-i draws power from the camera mount. No additional cable is required.

Clamping Lock Ring. The Prolock-i features a PL-style clamping lock ring on the Canon EF mount, assuring that the lens will not shift in the lens mount.