Valley Enterprises 2.1mm (Inside Diameter) x 5.5mm (Outside Diameter) DC Power Coupler Female to Female

I'm not sure how this could not get either 1 or 5 stars - it either works or it doesn't. Anyway, I have 2 male 2.1mm things plugged into this, and they work just fine. I use this to plug an adapter for my  Microsoft Surface Pro 3 (128 GB, Intel Core i5)  into  Anker Astro Pro2 20000mAh Multi-Voltage (5V 12V 16V 19V) Portable Charger External Battery Power Bank for iPad Air, Mini, iPhone 6, 5S, 5C, 5, 4S, Samsung Galaxy S5, S4, S3, Note 3, 4, HP, Dell, Acer, Asus, Toshiba Netbooks, Notebooks and many other devices (Apple adapters - 30 pin and lightning, not included)  using  XIEMIN Portable Power Adapter Charger Charging Cable for Microsoft Surface Pro 3 12 Inch Tablet (Pro 3 Charging Cable)  .

Works perfectly for idiots like me who run the wrong end of the CCTV cable out to the camera only to find two female power connectors at the camera side and two male connectors at the DVR side. I did this twice in a four camera run (and knew better). Check the labels on the end of the cables people! They actually have important things written on them. Anyway, Valley Enterprises to the rescue with their male-to-male and female-to-female power coupler products. If you've made the same blunder and your power connectors are 2.1mm this is what you are looking for. Don't forget to pick up your male couplers as well. Valley Enterprise carries those too: https://www.amazon.com/gp/product/B00B1JLN28/ref=cm_cr_ryp_prd_ttl_sol_0

My son uses this with his sound system. Works fine.

I waited for years for Anker to make an appropriate connector for a solar charger, and finally I bought a solar panel and used this connector to connect the solar panel to my Anker Powerhouse. Finally a solution that works. I am able to charge the powerhouse now!

Yes I was saved by Valley enterprises when I found out I installed one extension backwards I start looking for this kind of connectors and they fit and work perfectly, 5 STARS for the time, frustration and headaches you guys saved me.

Used to replace my damaged hue led light scrip power supply.Perfect solution!

The Valley Female 5.5/2.1mm Coupler rates five stars for many application. In my application it had to fit in a hole that houses the male connector. Unfortunately the diameter is too large for it to fit. If you have a similar application the Jacobs coupler is smaller and will probably fit. It does in my application. If you don't have size limitations this couple will work fine.

So I did a DIY Swann security cam install on my house when the siding was getting redone.... and I installed the cables backwards, all of them.... Needless to say these saved me from back-pulling, which would have been a major PITA. These work great and I've got no complaints.