bellhanger's drill - side and front view
Bellhanger's Extension Drill Bits are designed for drilling holes through masonry, concrete block, etc... so wiring can be threaded through these holes for cable TV, telephone lines, alarm systems, computer networks, and other electrical installations. Drills have a hole in the flute, sometimes called a fish eye, for connecting wire to the drill and then used to pull or fish wire, cable, or pipe through the wall. These drills are also known as Bellhanger Drill Bits or Bell-Hanger's Bits, Installer Bits, Feeler Bits, Fishing Bits, Skylight Drills, Spotlight Drills, Installer's Feeler Bits or Wire Installing Drill Bits.
Bellhanger's Drills - Flexible Shaft - High Speed Steel page 107
Flexible Shaft Bellhanger's drills are actually a combination fish tape and drill and make wire installation fast and easy. They also can be used to drill holes in places where shaft cannot reach in a straight line.

Bellhanger's Drills - Flexible Shaft - Carbide Tipped page 107A
Carbide Tipped Flexible Shaft Bellhanger Drills are actually a combination fish tape and drill and make wire installation fast and easy. They also can be used to drill holes in places where shaft cannot reach in a straight line.

Bellhanger's Drills - Flexible Shaft - Auger Tipped page 107A
Auger Tipped Flexible Shaft Bellhanger Drills are actually a combination fish tape and drill and make wire installation fast and easy. They also can be used to drill holes in places where shaft cannot reach in a straight line.

Bellhanger's Drills - Flexible Shaft - Threaded Flute page 107A
Threaded Flute Flexible Shaft Bellhanger Drills are actually a combination fish tape and drill and make wireinstallation fast and easy. They also can be used to drill holes in places where shaft cannot reach in a straight line.

Bellhanger's Drills - Straight Shaft - Carbide Tipped page 108
Straight Shaft Carbide Tipped Bellhanger's Drills have standard carbide tip for rotary or percussion drilling in masonry, tiles, brick, etc. Wide spiral flute for fast dust removal. Hole in flute for pulling wires.

Bellhanger's Drills - Straight Shaft - High Speed Steel page 108
High Speed Steel Bellhanger’s Extension Drills are designed for drilling holes through walls, studs, flooring, door widths and frames so wiring can be threaded through these holes for cable TV, telephone lines, alarm systems, computer networks, and other electrical installations. Drills have a hole in the flute, sometimes called a fish eye, for connecting wire to drill and then used to pull or “fish” wire, cable, or pipe through the wall. High speed steel drill point easily drills through nails, sheet metal, etc... They are also used in boat building for drilling long bolt holes in the stem, keel and deadwood as well as drilling holes for drifts in rudder and center boards.