Also provided are plates to form zigzag air passages by blocking {HEAD ~ a space} between the inner cover and {TAIL ~ the outer cover} 
between
Also provided are plates to form zigzag air passages by blocking { HEAD ~ a space } between the inner cover and { TAIL ~ the outer cover }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL