The 11K5017-JCNB is a Style 5017 control knob accessory manufactured by Grayhill, designed as a standard fit for Grayhill encoder and rotary switches. This knob features a spring clip (press-on) version with a shaft diameter of 0.125 inches or 0.157 inches (4mm), and is available in black or gray color options. The knob dimensions include a top diameter of 0.440 inches (11.2mm), a bottom diameter of 0.350 inches (8.9mm), and a height of 0.500 inches (12.7mm). It is constructed from nylon material and is ideally suited for optical and mechanical encoder applications, providing a reliable interface for user control in instrumentation and automation systems.