精品乱色一区二区中文字幕_美女视频永久黄网站在线观看_中文少妇按摩被按摩高潮_国产一级浮乱片视频_九七影院午夜福利_久久免费一级毛片_西西人体大胆扒开下部337卩_亚洲九月天堂av_亚洲AⅤ无码精品色午夜黑人_美女被免费视频网站

1, change the shape of the surface of the plastic handle, for example, you can make the middle of the handle relatively fine, to improve the stiffness and bending resistance of the handle. The longitudinal groove can eliminate the possibility of deviation or deformation of plastic handle under load.
2. Make the thickness of the plastic wall uniform, try to make the appearance of the handle symmetrical, reduce the extreme stretching point, and use the excessive arc in the excessive place.