Such a device is useful in making compound bends in {HEAD ~ electrical conduit} to ensure that the bends keep each end of the conduit in {TAIL ~ a common, or vertical plane} 
Such a device is useful in making compound bends in { HEAD ~ electrical conduit } to ensure that the bends keep each end of the conduit in { TAIL ~ a common , or vertical plane }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL