Gardner Bender 8 Awg Ring Red (5-Count) in the Terminal Wire Connectors department at Lowes.com
4 Gauge Wire Ferrules Kit for Car Audio,4 AWG Insulated Wire Ferrule Connectors (EN25-16),Cable Ferrule Terminal Connectors Crimp Red Black Blue Yellow Green Wire Furrels 100PCS,lkelyonewy: Amazon.com: Industrial & Scientific
WindyNation 4-Gauge 5/16 in. Pure Copper Cable Lugs (10-Pack) CF-4G-56-10PC - The Home Depot