This is a 200 foot long electrical wire pull, also known as a "Fish tape" .
These are used to reach over walls and ceiling, to get wires through conduit pipes, and basically to assist in getting wires access to a location where you are NOT able to open the walls and floors.
This tool features a 3/16" wide by 1/16" thick flexible spring steel pull blade which makes it ridged enough to be pushed through fiberglass insulation in walls and ceilings and to bend around radius conduit pipes without kinking. The spring steel also makes the lade uncoil nearly perfectly straight and recoils quickly and easily.
The tool features a heavy-duty ABS plastic case the is virtually crack proof, light weight, and heavy-duty handle makes rewinding it easy.