88 frame TC88K 1.295kg/m88 leaf TC88S 0.794kg/m88 "Wang" frame TC88WK 1.658kg/m88 upper frame TC88GK 0.967kg/m88 upper middle style TC88ST 1.05kg/m88 screen leaf TC88SS 0.45kg/m88 air shutter TC88FG 0.22kg/mangle 90 degree 1.10kg/m