Double-vacuum, hollow glass upvc windows selled in China in fact is he original glass washed with double-sided tape around the stick is good, put one in from the glass on the top In the connector marked with plastic, without rest assured that in a transparent tape over 4 weeks. PVC can be directly changed, aluminum alloy-is this what the outside market on the so-called "double-pane insulating glass" is actually "two-tier glass," and what from pumping oxygen, what is filled into the gas, Zhou ring containing desiccant (molecular sieve) aluminum frame, are Che Dan, shameless profiteers Huyou consumers from profiteering. Sound effect from the current point of view, "two-tier glass" effect of the noise is still very good, all the doors and windows locked up, feel the sound more than the time window reduced more than 90% tested noise over 30db or so. Although not all screens away, but the effect was at least more than twice my house under the flight paths in Hongqiao (Wanke City Garden), the aircraft soon landed an altitude of 1,000 meters below the below the sound can be basically negligible in. So advised consumers not deceived more wasting money. Recommendation: double-glazed soundproof effect is good, but the heat, ultraviolet radiation effect is not well separated. If you coat the inside of the glass paste glass membrane, the thermal insulation effect is more prominent, but also effectively block 99% of harmful ultraviolet rays, and to prevent the breakdown of flying glass.