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. Some common signs of a broken or failing switch are: 1. Tool has completely stopped functioning - it will not turn on 2. Tool operates intermittently, requiring multiple tries on to turn on, until eventually it wont turn on at all Variable speed function and electric braking arent working properly Trigger Switch Part Number 153609-00 This switch is a compatible replacement for the following for DW708 Cross Cut Miter Saw Types 1, 3 & 4 ONLY. Product Name:Trigger Switch Part Number:153609-00 Applicable Model:For DW708 Cross Cut Miter Saw Types 1, 3 & 4 ONLY. Note: Installation guide not included, we strongly recommend you seek professional installation. Please check as much as possible to make sure the item is what you need. Tips:The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use. Colour:As Shown Material:Plastic Package Contents: 1 * Trigger Switch Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.