主框 meaning in English

main ring

Main frame adoption from accept tightly a conceal type is solid to connect a technique , conjunction piece inside place , the product isn ' t easily aging , not only increasing the service life of the product , but also making external appearance more beautiful
主框采用自收紧隐藏式固连技术，连接件内置，产品不易老化，不仅增加了产品的使用寿命，而且使外观更加美观。