THe Zero-Cross Distributor spins on a double-sealed billet housing with a polished steel shaft and 1.587'' instrument grade bearing that provides zero shaft end play! Featuring a unique reluctor assembly made up eight indivdual cylinder tabs that feature a magnet assembly. Each tab can be adjusted up to 6° while the secondary pickup can be adjusted +/-4° from the primary. It also incorpates a ''zero-cross'' trigger technique that delivers accurate timing at any rpm. Must be ised with the Interface Contol Box (121-83581) and an MSD Ignition Control.