Binoculars

thumb|upright=1.35|8×42 roof prism binoculars with #Accessories|rainguard and opened tethered lens caps

small telescope, often used for studying birds and nature in daylight

thumb|The reticle of a PSO-1 scope mounted on a Russian SVD [[designated marksman rifle]] thumb|A comparison of different reticles used in telescopic sights thumb|Measurement graticule in an optical microscope thumb|Reticle of Bell & Howell Pocket Comparator thumb|Reticle accessory (PD-8) used in sniper rifles A reticle or reticule, also known as a graticule or crosshair, is a pattern of fine lines or markings built into the eyepiece of an optical device such as a telescopic sight, spotting scope, theodolite, optical microscope or the screen of an oscilloscope, to provide measurement reference

thumb|200px|right|Galilean type Soviet-made miniature 2.5 × 17.5 monocular thumb|200px|right| Diagram of a monocular using a Schmidt-Pechan prism: 1 – Objective lens 2 – Schmidt-Pechan prism 3 – Eyepiece

small, usually compact, binoculars intended for indoor use