There are a couple of sellers who have PZ5123 crystals for sale on ebay with a "defect" where there is a line below the Omega symbol in the center of the crystal. Here is a picture: Those pictures are from a different seller, but the defect is pretty identical to the one on the crystal I purchased. Neither myself or my watchmaker could get this crystal to fit my 136.017. I contacted the seller to ask if he's sure it is a genuine Omega crystal, and he responded it is and said I need to remove the bezel from my watch to fit the crystal. The 136.017 is a unishell case and does not have a removable bezel. The seller responded with these pics to assure me his crystals are genuine: Do you think these crystals are genuine? The one I received doesn't seem to be perfectly round, so maybe that is another "defect" that is causing it not to fit properly? I even removed the movement / dial from the case to and still couldn't get the crystal to fit. I'm also frustrated, because there was no mention of the defect / line next to the Omega logo when I purchased this item, but the seller added it when the auction was relisted. Any insight would be appreciated. Here are links to the auctions: Seller I bought from: https://www.ebay.com/itm/Crystal-Om...366950?hash=item3d9cb8e0e6:g:WlcAAOSwrpJcG2YZPurchases made through these links may earn this site a commission from the eBay Partner Network Other auction: https://www.ebay.com/itm/OMEGA-Dyna...353316?hash=item3fc8982324:g:KAcAAOSw6VRaQq0hPurchases made through these links may earn this site a commission from the eBay Partner Network