The 87-704 is a 20 mm diameter circular Window, specifically a Flat Window, from Edmund Optics. This Window is made of Magnesium Fluoride, identified as "magnes dod-1984-n-o" in the Material ID.
The Window has a base shape of a Thin Lens, with a diameter of 20 mm and a thickness of 2 mm. The lack of coating indicates that this Window is uncoated, which may be suitable for specific applications where coating is not required or preferred.
The Window is designed to operate at a wavelength of 587.6 nm. The weblink provided leads to the product page on Edmund Optics' website, where users can find more information about the product, including its current availability and pricing.