f) said second flat side having {TAIL ~ a second hole} complementary to said {HEAD ~ first flat side hole} with a catch; and 
f ) said second flat side having { TAIL ~ a second hole } complementary to said { HEAD ~ first flat side hole } with a catch ; and
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH