I have a Pro I purchased in December. When I mounted it, one of the mounting screws shaved off a metal ring from the optic. On further inspection, I noted imperfection on the underside of the screw head with a burr projecting out of the side. I called Sig and customer service promised me a free replacement set of screws. After almost 4 weeks, I called them again because I had not received the screws. I was told they were out of stock and they would email me that day with more information. Still haven't heard anything. Not too impressed with the customer service so far. I looked on their website today. Apparently, they are asking $24.99 for a set of mounting screws. You would think that $24.99 mounting screws would have better quality control.