***LIMITED ITEM PLS ALLOW 4 BUSINESS DAYS HANDLING TO SHIP*** Large 500 MFD 25 VDC ignition capacitor regulates light intensity. It has a positive wire lead and the case is grounded. The case measures 1 inch in diameter x 2-1/4 inch long with mounting screw tab. *NOTE: Mounts on stock XLCH models under the seat on the left side. The wire goes to the positive terminal on the horn feed. This allows horn sounding when headlamps are on. Gives an extra current boost when horn is blown on magneto model sportsters without a battery the wire attaches to the Bosch 12V regulator terminal inch61 inch. *NOTE: For use on Magneto Sportsters with 12 volt generator. There is no battery to regulate headlamp intensity. *NOTE: For use on magneto Sportster with a 12 volt generator and no battery to regulate headlamp inensity. FITS HARLEY: 1958-1969 XLCH, Regulates light intensity