Butt connectors come with a wide variety of names. They can be called butt splices, wire connectors, wire butt splices, butt crimps, or just plain butts. Either way, butt splices come in a variety of configurations. How do I choose the correct splice for my application?

Vinyl insulated butt splices are typically the most economical of the insulated wire splices. Use these when no special protection or characteristics is required.

Nylon insulated butt splices provide higher temperature and better durability than vinyl. They also have a seamless crimping barrel for maximum crimpability. Our seamless nylon butt connectors come with either a straight or flared barrel insulator.

For the maximum protection against environmental exposure, use Heatshrink Butt Splices to completely seal the splice.

3M Scotchlok Waterproof Connector
These connectors are great for connecting flexible LED Strips together without the need to solder.  They can also be used to connect to RGB controllers. 
Additional Information:
~~The connectors are filled with corrosion-resistant sealant at the factory to protect the connection against air and moisture.
~~There are two types, the 2-3 wire type UR-UR2 (red) and the 2 wire type UY-2 (yellow)
~~19-26 AWG wire size
~~To connect, you insert 1" of the wires into the connector, and then crimp with pliers
If you would like to see detailed instructions on using these connectors, please use this How-to PDF Manual Making waterproof connections using butt (crimp) connectors