thanks! so the one you're looking at has the regular sights but already have a flash hider?..When I 1st bought the 1st gen ones I told myself they should atleast installed a flash hider, so when i heard that they are coming out with one i figure i'm getting one again eventually, then i saw this one + the buis sights , so for me its an improvement becs it cost money to have them threaded and the sights is pricey to and there is no way i will shell out that kinda money, so i thought 510 is decent price NIB..