The STAN-SSH High-reflectivity Specular Reflectance Standard is a mirrored, fused-silica standard that can be used as a reference when measuring surfaces with high specular reflectance values such as optical substrates, optical coatings, machined metals and semiconductor materials. The STAN-SSH provides an ~85-90% reflectance across the 200-800 nm wavelength range and an ~85-98% reflectance across the 800-2500 nm range.