These are the "standard" size (4.0mm) banana plugs used on all kinds of electronic equipment, including almost all of the 12 volt field battery chargers, balancers, and other equipment sold for use with radio controlled models. They are solderless, and feature a female hole in the insulated housing that will accept another banana plug inserted into it, which allows a convenient way to stack or daisy-chain plugs together in those instances where you only have one set of female jacks available to plug them into.
These are the same excellent quality gold-plated banana plugs we use on our 12 volt Power Distribution Box. They are solderless, the wire is inserted into the end of the plastic housing and a set screw tightens down on the wire to provide a solid mechanical and electrical connection. The opening is large enough to handle an extremely large-gauge wire, I think perhaps as large as a 10 or maybe even an 8-gauge. The wires could be soldered to the connector if you prefer, I'd recommend that you slide the plastic housing down the wire before soldering to keep the heat of soldering from distorting it. They can be stacked together by simply plugging another jack into the hole that's in front of the set screw, just keep in mind the total current you'll be drawing from the combination of plugs if you stack them together, and don't overload them. The plastic housing on these plugs is much thicker and more rugged than a lot of the versions you may find at your local radio-equipment store, they'll hold up well in high-current applications.
Sold in pairs only, 1-Red & 1-Black.
4.0mm Banana Plugs
NOTE: I recommend that you "tin" the wires before inserting them into the jack and tightening the set screw. Strip a small amount of the insulation off the wire, about 1/8", twist the wires together tightly with your fingers, and heat the bare portion of the wire until solder placed on the other side of the wire melts and flows around the wire strands to cover them. (Here's a secret for good solder joints: don't heat the solder directly with your iron, use the iron to heat the wire or joint, and let the wire heat the solder until it melts!) This will keep the wire from crushing when you tighten the set screw, it will prevent the wires from corroding or oxidizing, and the soft solder will make a much better connection to the set screw than just the bare wire. Use rosin core solder ONLY!
Weight: 6 grams (per pair)