A small heavy weight with some means of attaching a line at one end. It is used for finding the vertical or perpendicular line to a horizontal plane.
NSN 6650-01-107-7553
NSN 6240-01-618-7818
NSN 5975-01-552-1812
NSN 5950-00-981-9047
NSN 5895-01-065-2336
NSN 5950-01-371-1296
NSN 6220-00-435-9003
NSN 5930-00-701-7665
NSN 5910-01-469-0837
NSN 5999-01-437-5475
NSN 6145-00-553-8196
NSN 6645-00-091-7353