AK S74U Rail
Rail is machined from aircraft grade Aluminium alloy EN AW 7075. No need for drilling holes into bolt cover, no need for special tools. Just klamp it on rear sights base and tighten up 2 screws. Also you dont have to take the rail or Red Dot mounted on it down during cleaning of your gun.
In case of emergency (empty battery, damaged optics sights) you can still use original iron sights.
Recommended are small 20mm tubular Red Dots (SigSauer, Holosun, Aimpoint, Vortex).