Amazon.com: cablecc Locking Waterproof CAT6 RJ45 Female to Female LAN Ethernet Network Extension Adapter Coupler : Electronics
1-Port USB 1.1 Over Cat5 Superbooster™ Extender Dongle RJ45 Female to USB B Male Receiver | USB Extension Cables and Devices | USB Cables, Adapters, and Hubs | USB and PC
DELOCK 85124: Adapter RJ45 female > RJ45 female panel-mount Cat.6 UTP at reichelt elektronik
Ethernet RJ45 Female Socket Push-Terminal Block : ID 2912 : $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits