Serviced by Canon recently with brand new Servo. Motor's where replaced as well as a factory interior clean. This Zoom Lens is pristine operating condition and free of any blemishes. 

Here is link to a PDF for more details for the family of lenses, along with a list of compatible servo-remotes and accessories. 

https://www.manualslib.com/manual/538423/Canon-High-Resolution-Lenses.html?page=8#manual