findyouled 20 Pairs MC4 Male/Female Solar Panel Cable Connectors The Conductor pin is tinned Copper It makes a rock solid connection after you crimp the pin to the wire, and these are operated perfectly under heavy load No Longer To Deal With Fixing The Connectors On The Roof The one O ring on connection is perfect to seal out water and dust to prevent corrosion and still able to disconnect if needed, and These connectors will survived rain, high force winds and snow for more than 20 years!! No Instructions In PackageBut with the help of a You Tube video,it is easy to learn how to use these MC4 solar panel connectors. If you want good solder tool for this connector ,pls look at the Kester 951 10ml Soldering Rosin Flux Pen , see ASIN : B004X4KOWS . If you want photovoltaic wire for the connection , see ASIN : B008JHXF4O .