Accel Electronic Ignition Distributor For Harley Big Twin 1936-1969 Features: Lightweight billet aluminum construction 12 V unilite ignition with fully adjustable advance allows faster and easier starting Features advance curves, rev-limiting and high-spark output Can be set to run either in a single-or dual-fire mode No head removal when using stock heads Made in the U.s.a. Requires graphite plug wires and resistor spark plugs.