sliding sash window

sliding sash window product detail: 1.fenglv 789-type *thickness: GB 1.4mm *fenglv 789:retaining 5mm higher than 788, good waterproof *the following track and the top track are all wide , can withstand a certain pressure *double pulley with good fluency 2.double glass *high-grade warm insulation for examp:double hollow glass, add hot water, not hot cup outside *not easy to condensation double glass istemperature buffer *noise barrier