| 摘要 |
According to an aspect of the present invention, a staff cradle comprises: a main body of which one side is opened; at least one extension plate which is accommodated in the main body to be vertically elevated and extended to an upper portion of the main body; and a laser director coupled to the upper portion of the extension plate and configured to receive a laser horizontally irradiated from a level machine wherein the laser director is formed on a front surface. |
