I can't see open sights worth squat but tried a WGRS on one of my UMags anyway. Took it off and sold it to another White owner. I could actually do a tad better with the factory sights. Wish someone would get one of those XSSights Weaver backups or the NECG rear peep. I think either one should work pretty well on the UMags but won't be the one acting as guinea pig - wouldn't be any point to it with my eyes.