Best Glide ASE Military Grade Glass Signal Mirror (Mark 3) The Best Glide ASE Military Grade Glass Signaling Mirrors are the Mark 3 Emergency Signal Mirrors MIL-M-18731E Type I (2 x 3) and Type II (3 x 5). The Type I (2 x 3) carries the designation NSN: 6350-01-455-6695 and the Type II (3 x 5) carries the designation NSN:6350-01-455-6671. These military grade signal mirrors are manufactured in the U.S.A. from highly reflexive glass. These are military approved and issued; it was designed for downed pilots and can be seen for miles. Their compact size and lanyard allow for amultitude of carrying options (i.e. pockets, packs, and around your neck) Sold Separately: Please see the Best Glide ASE Military Glass Signal Mirror Holder (ASIN: B076MHZP4K), which was designed to fit the Best Glide ASE Military Grade Signal Mirror (size 2 x 3 only).