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