This is a dwell and tach tester made by Sears company . will work on a 1 2 4 6 & 8 cylinder engines, great for setting up your points checking if the battery’s charging RPM testing This is a necessity perfect for maintaining and tuning all non-computerize, vintage vehicles and motorcycles pre-1989 model years  You can’t get these in the store anymore and it’s still a required tool. Best part is that it doesn’t need an app or any software to operate plug-n-play! vintage in the original box 
