Olivon 100mm ED APO 100mm f6. 600mm focal length. Utilizing, S-FPL51 glass in a doublet refractor encased in an aluminum tube and includes an excellent aluminum case. Advanced 2-element objective lens system minimizes color aberration. Fully multi-coated optics ensures utmost light transmission. Patented 2.7“ Rack & Pinion Hybrid – Drive. CNC machined aluminum body and focuser. Deluxe white high-glossy anodizing finish. Retractable sunshade. Includes an aluminum case. Diagonal not included.