YSW 400 T Thermally Broken Sliding Window with Monolithic or Insulating Glass Dependable Thermal Efficiency YSW 400 T is an architectural grade (AW) rated sliding window that offers ease of operation. The window is thermally broken by YKK AP MegaTherm® iso strut technology to conserve energy and reduce operating costs. The window has standard heavy-duty hardware that provides years of worry free operation. Product Options & Features n n n AAMA/WDMA/I.S.2-97 w HS-AW-40 rated Available configurations: OX, XO, OXO, & XOX Accepts 1 " insulating glass n MegaTherm® iso strut thermal break n Standard heavy-duty hardware n YFW 400 TU fixed lites available above, below or next to the sliding window n Head/jamb receptors, & stacking mullions