The strap 26 may be fabricated of {HEAD ~ a rigid material} such as {TAIL ~ a metallic or plastic material} or alternatively of a flexible material 
such as
The strap 26 may be fabricated of { HEAD ~ a rigid material } such as { TAIL ~ a metallic or plastic material } or alternatively of a flexible material
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH