Check the listing for details. EddyFi Technologies 20.8mm/20m ECT Standard Bobbin Probe - Olympus Zetec Evident. Condition: New – Open box. Listed at 699.99 USD. EddyFi Technologies 20.8mm/20m Standard ECT Probe. -EddyFi Certification Paperwork. The cables also use a strong, highly kink-resistant nylon, which is ideal for manual push-pull operations. -ECT 20.8mm Probe w/20m Nylon Cable.