• Package-RJ45 Port Dust Cover Anti-dust Caps, Black Silicone TPE rubber, 50 Pack
• Installation-Easily Insert into your RJ45 Ports to protect your network switches and fiber optic devices, and easy to remove with tab.
• Application-RJ45 Cover fits into all Ethernet Port RJ45 and it protects the RJ45 female jack from dust and oxygen

Differences between RJ45 Cover and SFP-A SFP-B SFP-C Cover

• RJ45 Cover TYPE: for all the Ethernet LAN RJ45 Port Jack protective caps.
• SFP-A B C Cover TYPE: for all the opening SFP SFP SFP28 slot on your Ethernet devices.

Those are ALL fit for network routers, switches, computers, and network wall outlets. Ethernet networks cards and media converters, Patch Panels and computer devices.;