Helps protect the surface of The MK1 Lens (a.k.a. The Death Lens / The Mark 1 Lens / Century Precision Optics DS-FEWA-00 0.3x Ultra Fisheye Adapter Lens). -100% unobstructed field of view (no vignetting) -Straightforward design and easy to attach -Outside coated with scratch resistant military grade hard coating Item includes: 1 microfiber carrying pouch, 1 attaching rubber band, and an extra rubber band.