The 16004 Open is a precision-manufactured Single Row Deep Groove Ball Bearing featuring a space-saving thin-section profile without seals or shields. With a 20 mm bore, 42 mm outer diameter, and an 8 mm width, it is engineered for compact mechanical assemblies where external contamination is controlled. Because it lacks closures, this open bearing generates the lowest possible friction, allowing for extremely high rotational speeds and unrestricted access to external lubrication systems. It efficiently supports both radial loads and moderate axial loads, making it an essential component for oil-bath environments, enclosed gearboxes, and precision instrumentation.