Tap reseaters are plumbing tools used to repair water taps.
Tap reseaters are hand tools, but there are attachments available that adapt them for use with a drill.
There are two different designs of tap reseater, but the variation does not affect performance. They are for use on different tap designs. (see What tap reseater sizes are available?).
Tap reseaters are used to fix one of the possible causes of a leaking tap. A leaking tap can be caused by multiple things and is dependent on the type of tap you have. A leaking tap is most commonly caused by general wear and tear of its parts.
Tap reseaters repair compression washer taps. The flow of water from a compression washer tap is stopped and started by the movement of a rubber stopper (washer) against a hole (seat) inside the tap body. Tap reseaters repair the seat of a tap.