Polaris 600 MCM - 6 AWG Bagged Insulated In-Line Splice, Black ISR-600B - The Home Depot
Wire Terminal 1/0 - 6 AWG Tinned Copper Terminals
POLARIS nsi - 6 AWG, Class B & C Wire Compatible, Aluminum, Hex Split Bolt Connector - 42550202 - MSC Industrial Supply
Amazon.com: 1 Set 50Amp 2 Poles Power Connector Plug Grey w/Terminals for #6 AWG Wire Anderson Compatible [2 housing+4 Terminal pins] (pin for #6 awg Wire, Grey) : Automotive
6 Wire x 1/4" stud ring connector terminal, non-insulated | NAZ Solar Electric