The height of teeth of the toothed arch block is approximately equal to {TAIL ~ the height} of teeth on {HEAD ~ the ratchet} wheel 
The height of teeth of the toothed arch block is approximately equal to { TAIL ~ the height } of teeth on { HEAD ~ the ratchet } wheel
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH