Each side may also have {HEAD ~ a height} between {TAIL ~ about 5 μm} and about 15 μm 
between
Each side may also have { HEAD ~ a height } between { TAIL ~ about 5 μm } and about 15 μm
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH