This item can be used to mass-place arrays of blocks or to retrieve blocks in the world.
You can open its GUI by Numpad 0. There you can choose the mode; placement mode requires music disc 'blocks'; retrieval mode requires music disc 'ward'; the discs must be put into Manipulator's slots in any order.
Using mode 'place': right-click on a block in the world which you want to mass-place; right-click on start position; then as you move the mouse away, there will be outlines of blocks displayed at positions to place at; right-click on the end position to perform placement. Blocks that are inside the area of placement will stay.
Using mode 'retrieve': right-click on a start block; the outlines of blocks to retrieve will be displayed; right-click on the end block to perform retrieval. It won't retrieve blocks that have block entity.
Shift + right click to reset the manipulator.