The 1.25" Enhanced Aluminum mirror coating provides a 96% reflective surface across all but the extreme red/blue ends of the visual spectrum. The enhanced coating provides extra reflectance versus competing standard aluminum coatings. The final coating stage applies a tough overcoat to protect the aluminum. The diagonal body has the same features as the Everbrite. All diagonals feature brass clamp rings and filter threads. The Enhanced Aluminum diagonals are good budget alternatives, especially where a prism diagonal might otherwise be considered.
The mirror substrate is figured to a surface accuracy of 1/10 wave flatness. To ensure performance, every mirror is optically inspected under conditions far more critical than a diagonal mirror is ever used in typical telescopes. The diagonal body is machined from a solid block of aluminum, and so permanent alignment is assured. The one piece body construction also means heavy accessories can't force the diagonal body to "unscrew" from the barrel as with other brands. Features brass clamp rings, anti-reflection threads and 1.25" filter threads.