Houseables Generator Extension Cord, Electric Wire, 3 Prong, 30 Amp, 250 Volt, Single, Black, 25 Ft, All Rubber, 10 Gauge, Heavy Duty, L6-30, Commercial, Electrical Power Cable, with Locking Switch - - Amazon.com
EFX 250-Watt Amp Wiring Kit 10-gauge power cable, with patch cord at Crutchfield
XS Power BIG3XP 250-amp Big 3 wiring upgrade kit at Crutchfield