Flame-Thrower Digital Rev Limiters work with any 4, 6 or 8-Cylinderinder engine using points, oe electronic or aftermarket inductive type ignition systems including Pertronix's very popular Ignitor and Ignitor II points replacement Systems. This digital microcontroller based unit provides a much greater accuracy (+/-0.01%) over analog Systems. There is no need for old resistor Style pills or chips, Pertronix's easy to use rotary switches adjust the rpm limit to an ultra fine resolution of 100 rpms. Pertronix's proprietary algorithms provides superior control of rev limits and a rapid response time to over rev limit events, preventing engine failure. rev Limiters come with multiple analog filters and One digital filter to prevent Coil noise interference from affecting the established rev limit. installation is a snap with a four wire hookup and easy to understand instructions. The rev Limiter's small size permits installation in even the Most crowded engine compartment.