Designed to fit the various iterations of the Exos-2 equatorial mount, the Explore Scientific Illuminated Polar Finder Scope has an illuminated star field reticle that clearly shows the four primary stars of the constellation Ursa Major (Big Dipper). To polar align your scope, simply line up the four dots on the reticle with the corresponding stars in the sky. Features such as red illumination with adjustable brightness to preserve night-adjusted vision make this an essential accessory to your compatible mount when used anywhere in the northern hemisphere.