The Parco 4000 series compound microscopes feature a 45° inclined sliding binocular or trinocular head, designed to reduce eye and neck strain. They are equipped with a 55mm - 75mm interpupillary adjustment, and a diopter adjustment on both ocular tubes to compensate for eye-strength difference when needed. They feature a quadruple nosepiece with four DIN achromatic objectives, which are parfocaled and parcentered to ensure the image stays centered and focused during every magnification change. For added safety, microscopes have a rack-stop which helps to prevent damage to slides and objective lenses, while the slip-clutch system protects gears from damage.