Ideal 30-163 Blue Twist On Wire Connector 6 AWG to 16 AWG (15 Pcs)
Ruikarhop Black Insulated in-Line Splice Connector(2/0-6 Gauge,7/32 Allen Hex),CU9AL Dual Rated for Copper and Aluminum Wire,6061-T6 Aluminum,Rubber Vinyl Coating,Rated up 600v: Amazon.com: Tools & Home Improvement
Gardner Bender WingGard Large Blue 14 AWG to 6 AWG Wire Connector (50-Pack) - Parker's Building Supply
100) Non-Insulated 8 to 6 Gauge Step Down Butt Splice Connector Uninsulated Wire Terminal - USA Made - Walmart.com
1PCS Insulated Inline Splice Connector 2/0-6 AWG Aluminum to Copper Wire Connectors Slotted Allen Hex Insulated Cable Connectors - AliExpress