[custom_frame_left][/custom_frame_left] SPT cable can be a 2 or 3 conductor cable that you can buy in bulk. SPT is an acronym for Stranded Parallel Thermoplastic. Generally speaking, SPT cable extension cords are cheaper to make than store bought extension cords. You can cut SPT cable to length and not have extra cable lying around. Generally speaking, you can make a drop cord cheaper that you …