Direct Burial Loop:
Generally made of non- metallic PVC flex conduit. They come in 4'x6',
4'x8', 4'x10' pre-made sizes. Any size can be made. The loop is
generally buried a few inches below grade. These loops can be placed
in the road bed prior to laying asphalt. Under concrete they are
placed above the rebar or re-mesh before pouring.
More than one loop can be connected to one loop detector. Find preformed driveway loops here.