Crane's breakerless ignition gives top performance and mileage without the gradual decline caused by wearing points and a tired distributor. You never have to reset your points again!
On the Crane system triggering is done by an infrared LED and chopper wheel. This completely eliminates the timing and dwell variation found in breaker point distributors, and is less susceptible to shaft wobble (common in older, worn distributors).
The Crane system has its own voltage regulator, is accurate to 1/100 of one degree, and each electronic component is used at only 40% of its capacity, for an extra margin of reliability. For all 12 volt, 4 cylinder models prior to 1975.
(Since distributors are easily switched between years and models, we show all the variations we have Volvo coverage for).