March Scopes MD Disk For Rifle Scopes 56mm Objective Black. This light reduction increases the scopes depth of field and prehaps more impotantly for competition shooters reduces the amount of seen mirage. Using a MD Disk at 60 or 80 power gives you a competitive advantage when the conditions turn bad and lets you see the target better than your competitor. Specifications for March Scopes MD Disk For Rifle Scopes: Manufacturer: March Scopes Color: Black Finish: Type 3 Hard Coat Anodizing Fabric/Material: 7075 Aluminum Fit: Universal Gun Type: Rifle Gun Make: Universal Gun Model: Universal Country of Origin: Japan Package Contents: March Scopes MD Disk for Rifle Scopes March Scopes DB269-0: MD Disk For Rifle Scopes 56mm Objective Black