Wire Connectors, 12 Pack Low Voltage Wire H tap 2 Way connectors 2 Pin solderless with no Wire-Stripping Required for Mid-Span Branching in Wires Connection 20/22 AWG Cable 0.2-0.5mm², by brightfour :
Working with Wire - SparkFun Learn
280 PCS Closed End Crimp Connectors - Wire End Caps - 22-10 Gauge – Wirefyshop