The Laylax HUD type sight protector is "Aegis" is an angled shield used to protect your red dot, magnified optic, or scope. The angled design better helps to deflect the power of the bb hitting the shield, keeping your sight safe. The "glass" on the shield is a strong, thin piece of acrylic to ensure its lightweight with a fair amount of flexibility to take impact. An added bonus is that it features a "HUD" or Heads Up Display style as you would see on a fighter jet printed on it. Mounts to Picatinny rail.