Used MSD six shooter ignition box assm. With this ignition box it allows you to retard ignition timing six times going down the track with six different timing retards. This box must be used with 8168 pro mag timing control. This box can be stacked if you want more timing retards than six. Box does not include wiring harness, or timing retard chips and but does include detailed instructions and rubber mounts. SIX SHOOTER BOXES HAVE BEEN TESTED BY FUEL INJECTION ENT. AND ARE IN GOOD WORKING ORDER.