202101 is a TNC male cap with chain designed to protect TNC connectors from dust, moisture, and environmental contaminants when not in use. The cap features a brass shell/body with nickel plating for corrosion resistance and durability. It includes a silicone gasket (red) for sealing, along with a brass chain and rivet, both nickel-plated, to keep the cap attached to the equipment. Key dimensions include an overall length of approximately 18.00 mm and a chain length of 100 mm. This protective accessory is commonly used in RF and telecommunications applications where TNC connectors require protection during storage or when ports are temporarily unused.