电动伸缩门由十多种配件组成。它的组成如同人体一样，各司其职，不可缺少。然而，伸缩门的大部分配件都是用塑料型材包装的。配件的内在质量，安装在墙上是看不出来的，配件的质量和价格有很大的差异，比如钢衬，钢衬是用来连接型材和钢衬与自身的塑料型材中的自攻螺钉。因此，在四宜也被称为塑钢门窗。钢衬是必不可少的。*明确规定，箱内钢衬的厚度不得小于1.2厘米，有的为1.0、0.8或0.6，有的塞满了从二手货中回收的废铁或汽油桶皮，有的甚至不穿钢衬。如果门内的钢衬达不到要求，时间一长就会变形。
The electric telescopic door consists of more than ten types of accessories. Its composition is like that of the human body, each performing its own duties and indispensable. However, most of the accessories of the telescopic door are packaged with plastic profiles. The internal quality of accessories cannot be seen when installed on the wall. There are significant differences in the quality and price of accessories, such as steel lining, which is used to connect profiles and self tapping screws between the steel lining and its own plastic profile. Therefore, in Siyi, it is also known as plastic steel doors and windows. Steel lining is essential* It is explicitly stipulated that the thickness of the steel lining inside the box shall not be less than 1.2 centimeters, some of which are 1.0, 0.8, or 0.6, some of which are filled with scrap iron or gasoline barrel skins recovered from second-hand goods, and some of which do not even wear the steel lining. If the steel lining inside the door does not meet the requirements, it will deform over time.
*强制性标准的出台提高了行业门槛，促使电动伸缩门企业提高技术水平，增强竞争力，形成了一批全国知名甚至*影响力的品牌，形成了非常明显的集群效应。目前，中国电动伸缩门行业的企业总数在*上非常高，占比接近10%。各类产品年产量基本能满足国内需求，出口量惊人。
*The introduction of mandatory standards has raised the industry threshold, prompted electric retractable door enterprises to improve their technical level, enhance their competitiveness, and formed a group of nationally renowned and even influential brands, forming a very obvious cluster effect. At present, the total number of enterprises in China's electric retractable door industry is very high, accounting for nearly 10%. The annual output of various products can basically meet domestic demand, and the export volume is astonishing.
