So a few weeks ago I have ordered iron sights for one of my rifles, the order for processed in timely matter, shipping a bit overcharged but whatever, then I installed the sights onto my rifle only to learn the height does not match and one of them has to go and be replaced with correct height. I contacted Marstar's customer service for correction and was completely ignored. This was my second purchase from them and I know there will NOT be a third one. I must point out the sights were for a straight picatinny platform and no rocket science was necessary to match up proper sights.