DELOCK 86589: Protection cap for RJ45 connector, black at reichelt elektronik
NTI cvr-rj45jck-k100 RJ45 Female Connector Covers, Black, 100-pack - Pro AV Warehouse
Amazon.com: ZYAMY 100pcs Blue RJ45 Adapter Cap for 6mm Ethernet Network Cable Connector Plugs Boots Cover Mini Protective Sleeve Crystal Head Protector : Electronics