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&Recently, the group's existing qualification of building doors and windows has been upgraded to the first level, and thus it can undertake the construction of various metal doors and windows projects such as aluminum alloy, plastic steel, etc. &It is reported that the qualification of professional contractors for metal doors and windows engineering is divided into grade I, grade II and grade III. The first level can undertake the construction of various aluminum alloy, plastic steel and other metal door and window projects; the second level It can undertake the construction of the following aluminum alloy, plastic steel and other metal door and window works with a single contract amount not exceeding 5 times of the registered capital of the enterprise, the metal door and window works of 28 floors and below buildings, and the metal door and window works with an area of 8000 square meters and below; the third level can undertake the construction of the following aluminum alloy, plastic steel and other metal door and window works with a single contract amount not exceeding 5 times of the registered capital of the enterprise, that is, 14 Metal door and window works for buildings with floors and below and metal door and window works with an area of 4000 square meters and below.