λ/4 wave first surface mirror glass offers superior precision compared to other first surface mirrors on the market. λ/4 flatness is achieved by producing glass , then coating with aluminum and the protective overcoat. Typically, what most of our competitors offer is simply on float glass, which is 4-6λ per inch. To the naked eye, the two mirrors look the same, but the quality of the λ/4 is immediately noticeable under magnification. The production of a high-quality optical component is an exacting process, requiring a high level of skill, quality equipment, and close attention to detail.