This is a premium quality shielded "keystone" jack coupler. This product has been carefully designed for shielded cables. Don't settle for less if you are running Ethernet in your home with jacks/wallplates in the walls. This is used inside walls with our pre-terminated (manufactured cables that already have connector ends on them) premium quality shielded ethernet cables. We use these often with clients and customers. Running pre-terminated cables is often easier and less labor-intensive than having to terminate ends on the cable. Either way works fine, but these keystone style couplers work great for this purpose!
The keystone jack coupler clicks into keystone jack wall plates (the plates with the square holes).