Street/strip vehicles, up to 6,500 rpm, polyester, black, Hyfire series, Promaster coi This high energy coil is designed for use with Mallory Hyfire Series Electronic Ignition Controls. This electronic Promaster coil has a fast rise time and long spark duration for improved performance up to 6,500 rpm with OEM ignitions and up to 8,000 rpm with aftermarket ignitions. An oil-filled polyester case reduces energy loss from spark arcing. Brass terminals and spark plug type secondary terminals provide secure connections.