Our Swarovski replacement hub is machined to fit perfectly on the mounting spindle of the EL, ELR and NL series binoculars. Designed to look like a factory part or even better with the matching notches shown on the Swarovski adjustment ring, these items are very well made like all the RYO equipment. Machined from Aluminum and anodized black, designed to replace the stock plastic hub. You can mount our harness split ring directly to the RYO hub or incorporate the use of our binocular rubber connection straps for a absolute silent fit. Made in America