The STS Parts 121578C1 6-Volt Voltage Regulator is a high-quality aftermarket replacement for IH Farmall and Delco 6V generator systems. Built for positive-ground, A-circuit configurations, it regulates charging at approximately 7.1 volts for consistent battery performance and long electrical system life. This flat-base, external-mount regulator uses L-BAT-F-GEN terminals and grounds through the base. It's perfect for restoring and maintaining vintage Farmall, International Harvester, and Allis-Chalmers tractors, as well as select Massey Ferguson and Cockshutt models with 6V Delco generators. Technical Specifications: System Voltage: 6 Volt (Positive Ground) Circuit Type: A-Circuit (Delco Generator) Voltage Set Point: 7.1V nominal (output 7–9 amps) Mount Type: Flat-Base, External Terminals: L (Lights), BAT (Battery), F (Field), GEN (Armature); GRD via base Condition: 100% New, Solid-State Type: Two-Unit Regulator Warranty: 1 Year Replaces OEM / Cross References: IH / Farmall: 121578C1, 360898R1, 354234R91 Delco: 1116807, 1116816, 1118291, 1118308, D645, D657 (VR1814) Prestolite: 8-291, GRX-291 Allis-Chalmers: 70228365 Lester: 9293 Applications: Farmall / International Harvester: C, Cub, Cub LoBoy (not 154/184/185), H, I4, I6, M, MD, O4, Super A, Super C, Super H, Super M, Super MTA, W4, W6, W9, WD6, WD9, WR9, 100, 130, 140, 200, 230, 240, 300, 330, 340, 350, 400, 450 Also fits: Cockshutt 540, Massey Ferguson TO-30 (6V Delco systems)