WIELAND ELECTRIC 99.416.6205.2 防尘盖/罩, 3 极, End Cover, Unused Male Connector
The is a black End Cap for covering unused male connectors.
Newark:
# WIELAND ELECTRIC 99.416.6205.2 Dust Cap / Cover, 3 Pole, End Cover, Unused Male Connector
Electro Sonic:
Connector Accessories Cover Black