HD Optical System: The entire optical system is specifically designed and adjusted to the fluoride High Definition objective lenses. This unique manufacturing method optimizes the purpose of HD glass in the new SLC. Magnesium Housing: Maximizes strength while being approximately 30% lighter than commonly used aluminum alloy housings. Monochrome Rubber Armoring: The new SLC series magnesium housing is now completely covered in a rubber armoring with 2 different textures for maximum protection and handling comfort. Compact design: The use of the Abbe-KA-nig roof prism system enables a more slender design for smaller hands and an all-round steadier hold. Mfg: Swarovski