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