Optical Window: Optically flat, double sides parallel polishing of the optical glass into a relatively high precision of the surface. Mostly it is used for the testing or assembly equipment's to allow light to get into the testing machine or the instruments. PHYO Optics provide many different type of windows using various optical material, like BK7, Fused Silica,Ge, ZnSe, Calcium, Sapphire or MgF. Including Parallel or wedge. Most of them with the AR coating to improve the transmission rate in display from UV to IR light. Some parts can be used in the laser system in a high flatness and surface quality. Reticle Scales Patterns: A reticle, also known as a graticule, scales, patterns, used in eyepiece of a sighting device, such as telescope, microscope, or oscilloscope, etc. They are engraved lines in the eyepieces, with chrome coating. The engraved signs including cross, dots, lines, circles, scales, or a combination of these. PHYO can make the engraving both for chemical etching or physical marking. With or without coating on the substrates. Both for positive or negative markings. Specially we can reach blue colour Chrome Coating on substrate get a clear image of eyepieces.