Lens box is secured or hang outfit at metope, metope bore deepness is not less than 50 millimeter, wooden tenon should embed bore, tail end extends the 10 millimeter inside the wall.

• 镜箱固定或挂装于墙面，墙面钻孔深度不小于50毫米，木榫应嵌入钻孔，尾端伸入墙内10毫米。