{HEAD ~ a second step} extending above {TAIL ~ the bottom surface} of said housing and positioned adjacent to said passage 
{ HEAD ~ a second step } extending above { TAIL ~ the bottom surface } of said housing and positioned adjacent to said passage
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH