These pickups are a great set to upgrade your bass. In my case a Fender Player Jazz Bass made in Mexico. Procedure is really simple as you only need the soldering iron to remove the old components (in case you do not want to cut cables). The set comes with all potentiometers of good quality that do not require soldering. Same as the pickups and other components. As the set is *Active* pickups, you will need a 9v battery, which in the case of the Fender Player Jazz Bass fits well in the slot available for wires. The sound is outstanding, really full, clear, bouncy and defined. They are versatile and provide a sound palette that could go from well distorted tones to more traditional ones with extra definition. Don't get confused because they are endorsed by Robert Trujillo of Metallica, these can for sure be used for metal with impressive results, but as well for many other genres with splendid results too. Worth every cent I paid for them. Even being my first EMGs, I very much recommend them.