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 {HEAD ~ the lower case} 
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 { HEAD ~ the lower case }
OTH OTH OTH OTH 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 HEAD HEAD HEAD HEAD HEAD HEAD HEAD