Brightfour Low Voltage Wire splice connectors - Pack of 12 Quick Solderless T Tap Connector 1 Pin,Rock Solid Connector for 24-20 AWG Cable for Vehicle/audio/video/Lighting and Automotive Uses - Amazon.com
Inline Splicing Wire Connectors with 3 Poles For 0.14-4mm2
MO Wrenching: How To Properly Splice Wires | Motorcycle.com