What is eccn number for a knob?

The ECCN (Export Control Classification Number) for a knob would depend on its specific use and materials. Generally, knobs used in industrial or military applications may fall under certain ECCNs related to mechanical components, while standard consumer product knobs might not require an ECCN at all. For precise classification, it's essential to consult the Bureau of Industry and Security (BIS) or relevant export control regulations.