Lance made the plastic-steel soundproof window at the earliest, and other brands followed suit, because all plastic-steel profiles are the same, and the quality can only be distinguished by the brand of profiles purchased. It is good to use conch profile, but it is immoral to use fake conch with poor steel lining. It can't be seen from the appearance, but you can call the profile manufacturer or have a bar code to verify it.

There are two kinds of aluminum alloy soundproof windows: Dingli School and Feisberg School. The sound insulation window of Dingli School is the earliest one, and other brands have followed suit. Fesberg was also the first one made by Fesberg, and other brands followed suit. The aluminum alloy profiles of these two companies are developed and designed by themselves, and ordinary aluminum alloy profiles are not used. But many people take profiles to the factory to open the mold, and the appearance is similar.

In addition, aluminum alloy pie also uses ordinary profiles as sound insulation windows. By increasing the thickness of profile and glass, good sound insulation effect can be achieved. The whole window is relatively thick, and it can only be a casement window, and the effect is not as good as that of other people's push-pull soundproof windows.