DESCRIPTION
The 2 mm Aperture Mask is an aluminum disc 8.75 inches in diameter. Its center aperture is 0.078 inches in diameter. It is one of three masks that ship with the Variable Angle Specular Reflectance Accessory (01860954). It is used on the accessory's second sample stage, opposite the stage for high-angle measurements, and allows you to study a small area of a larger sample .