I bought this based on the previous 5 reviews, I have a vintage Omega SeaMaster with 20mm lugs and they fit perfectly. I don't know why they suggest you also buy pens since they are included. I had to remove a link and adjust the pin on the clasp, but small eyeglass screwdrivers did the job easily. There was a problem with the delivery. It was registered as being shipped to a "Shipping Carrier" (USPS) in Hebron, Kentucky, but didn't show anything until it showed up at my post office 4 days later. Even Revain customer service asked me to order another even though it was lost. But both came.