This enables an engineer to test {HEAD ~ a telephone line} by simply clipping a crocodile clip onto {TAIL ~ the test contact member} and a wall member 
This enables an engineer to test { HEAD ~ a telephone line } by simply clipping a crocodile clip onto { TAIL ~ the test contact member } and a wall member
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH