RJ45 Cat5 / 6 Ethernet boot

RJ45 strain relief boot is a small plastic or rubber device that is attached to the end of a network cable (typically an Ethernet cable) where it connects to an RJ45 connector. 

The boot is designed to provide additional support and protection for the cable and connector, helping to prevent damage from bending, twisting, or pulling.

The boot typically slides over the connector and onto the cable, and is then secured in place with a small tab or clip. It may also have a small tab or grip area on the outside, making it easier to remove the boot if necessary.

Using a strain relief boot can help to extend the life of a network cable and connector by reducing the stress placed on them. It can also improve the appearance of the cable, making it look neater and more professional. RJ45 strain relief boots are commonly used in networking applications, such as in data centres, server rooms, and office networks, as well as in home networking setups.