Gardner Bender 14-8 Butt Splice Black in the Terminal Wire Connectors department at Lowes.com
UNDERGROUND-DIRECT BURIAL SPLICE KIT : UGSKIT2 | Lowe Electric
Underground General Cable Meter Wire Finder Tester Tracer Kit Tracking Underground Cables With English Instruction Manual - Circuit Breaker Finders - AliExpress
Small Pet Fence Wire Repair Kit - 10 ft / 2 splices
Underground Direct Burial Wire and Extension Cord Splice Kit for #10#12#14 AWG - 3 Wires - 3 Connectors, and 3 CLEAR Dual Wall 3M Heat Shrinks w/ 8" Long BLACK Heavy Dual