Signstek Y Branch MC4 Parallel Connector Adapter M/FF and F/MM (1)

Easy to install and does what you need. I installed a second 100 watt solar panel and using this cable kept the panels in parallel which in turn kept my voltage at a nominal 12 VDC output. If you wire the two solar panels in series instead of using this cable, you would end up with a nominal 24 VDC system. That sucks if your charging a 12 volt battery, or your charge controller expects 12 volts.

These worked out great. Because the ends split, it makes connecting multiple solar panels easy. I learned the hard way because the first set I bought were solid (plastic) and you couldn't connect multiple panels because the plastic connectors were too thick to fit next to each other when trying to connect. I would definitely get these again, and would suggest anyone setting up a system to do the same thing, instead of getting the fixed solid ones.

Got these to connect two 100 watt panels on RV in parallel. Due to the 25' 10 AWG wire run from the panels to the controller I decided to run them in series instead to increase volts which decreases amps and resistance, hence increased system efficiency. Only down side to running series is you need a MTTP controller, which I believe is worth the extra cost due it's increased potential gain, and if one panel gets shaded this becomes the controlling factor in the system performance. With only two panels close to one another I wasn't concerned. Nice connectors if you need them.

This is the best price I could find anywhere on a single set. These are genuine TUV-spec 30 amp solar panels cables configured into what seem to be a solidly-built, super useful "Y" adapter. The maximum spread between the two connectors at the top of the "Y" is 5 inches and the whole adapter is 11 inches from end to end, which is pretty standard for these adapters in this price range. If you need adapters with a slightly wider spread, they can be found on some sites with quite a bit of searching, but they will cost more.

Worked just as described. I didn't see sizing information, so I wanted to provide the info I tracked down to help anyone purchasing this product in the future. The markings on the wire state 1x4.0mm(squared), when searched online this cable showed is usually used in solar applications (as expected) and provided 2.6mm conductor diameter. A look up online showed that a 10 AWG cable has a conductor cross section of 2.58mm. So, this cable is very nearly the same carrying capacity of a 10AWG cable.

Well constructed high quality MC4 connectors with thick multi-strand copper wire - I know this because I cut the ends off and soldered ring terminals on the single ends to connect directly to screw down terminals on inverter. A few inches extra cable would have been nice but they worked for me. Great price too.

They arrived quickly and work as they should. I took off 1 star because as another reviewer mentioned the picture of the female connector does not match what you get. These are the standard type that require a tool to disconnect. This is not a problem for me as I don't plan to move them anytime soon or add more panels for at least 6 months. As far as a tool, pinching with needle nose pliers while pulling apart works for me. A dab of silicone lubricant before connecting aids in both connection and later disconnecting.

I was worried that the wiring of my four solar panels wouldn't reach, since I was wiring as a series-parallel system. But these Y connectors made the connections possible and have worked very well with my 400 watt system. A Great product that I can recommend! I would definitely buy these again!