The quick release button allows for fast and convenient vertical movement and the fine-focus adjustment knob is especially useful at high magnification. This model also includes an adjustable safety stop to prevent the microscope from touching the specimen. Its adjustable horizontal arm has a 15cm range with 360-degree rotation and the additional arm (RK-10-EX included) increases its effective range to observe larger objects. With these features, the RK-10A is the ideal accessory for precise orientation and positioning for maximum productivity and ease of use in a wide range of environments including industrial, scientific and laboratory settings.