cover is permanently marked 7.62 X 39 Ejection Port Dust Cover on both sides
so it is visible in open or closed position.
Mark your upper to designate the caliber with using a single lower with different uppers.
Fits AR-15/M4 Upper Receivers.
Laser EngravedMade In USA.
May occasionally have some variation in laser work.
Dust covers are true mil-spec and arrived to us in bulk bags of 500 each and coated with lubricant.