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