The Balmar BRS-2T-24 voltage regulator is designed to be used in conjunction with 24-volt, positive excitation (P-type) EXTERNALLY REGULATED alternators. The BRS-2T-24 voltage regulator provides an adjustable potentiometer that allows control of the regulator's maximum voltage limit. Adjustment ranges from 26.5V to 29.5V. Factory voltage setting is 27.5V. w/o Harness