Having flip-up lens covers for your scope's objective lens is a must in order to keep your scope lenses clean and clear. The Nightforce Flip-Up Objective Covers for NX8 optics is the perfect addition to your scope setup. The lens covers are made by Tenabraex, a trusted company with years of experience, and attach to the optic through a threaded adapter that locks them into place. Simple finger pressure allows them to open easily and lock rearward. Mfg: Nightforce