This Trigger Switch - (Eaton Style) is an over hang Trigger Switch with large button. It replaces Dewalt 153609-00 switch and is generally used on table saws and power tools with higher ratings; miter saws, chop saws, etc.
Switches are commonly replaced parts in power tools. A switch handles all on/off and variable speed functions. They also have a role in electric breaking; they can momentarily reverse electrical polarity. Because switches use mechanical internals, they tend to degrade and wear out over time, eventually requiring replacement. This particular switch comes as a worthy replacement because it offers high quality at a lower price tag.
NOTE: Some common signs of a broken or failing switch are: