Finally, the 16520 introduced a number of other design changes. The case https://www.iwhorloges.cz/ went up in size from 37mm to 40mm, a sapphire crystal was added, and the sub-dials https://www.crwmontres.com/ had added to them a thin outer metal ring, with a contrasting color for the running https://www.iwwatches.to/product-category/pilots/ seconds, chronograph minutes, and chronograph hours tracks.