{HEAD ~ An upper case} having {TAIL ~ an insulated inner surface} including a sidewall structure complementary to the lower case sidewall structure forms a lid for the channel and is insulated from the lower case 
having
{ HEAD ~ An upper case } having { TAIL ~ an insulated inner surface } including a sidewall structure complementary to the lower case sidewall structure forms a lid for the channel and is insulated from the lower case
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH