These JEGS Pro Series Distributors for small block or big block Chevy and Ford applications feature an internal HP electronic ignition module that's ready to run (external ignition box not required) and delivers twice the voltage to the spark plugs. SSR Pro Series Distributors have: premium maroon caps with brass terminals for use with male cap (or HEI style) spark plug wires, Hall effect triggers (integrated circuits with no moving parts to wear out), polished billet aluminum housings, and a performance advance curve with additional springs to customize the curve. The upper ball bearing and extra long oil-impregnated bronze lower bearing work together to reduce friction and provide stable timing.