SIENOC 20 Pcs RJ45 Coupler Ethernet Cable Extender Female to Female Straight Modular Inline Coupler (20 Packs RJ45 Female to Female Plug Coupler);

There is a female jack on both sides of the connector so you can plug a cable into the back, as well as into the front.
The couplers provide a full range of solutions for voice, home networking, home office, audio, video and more.

Feature:
Type : RJ45 female to RJ45 female connector
Plastic housing Gold plated contacts, straight-through wiring.
Material : PC/copper/Tin plated
Color : Grey
Standard: 8P8C (female-female)
Dimension: 34 x 15 x 21mm/1.35 x 0.62 x 0.82inch(L x W x H)