Superior Electric L50 Aftermarket Trigger Switch replaces Makita 651172-0. This switch can be found in many Makita circular saws and grinders. 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 switch proves to be a worthy replacement with supreme quality and a lower price to go with.