Cardboard backer is actually a folder that contains instructions.
Actron Compression Tester Kit 0-300 PSI Model A-1 Engine Compression Tester
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Actron Universal Compression Tester Kit 0-300 PSI Model A-6 Made is USA
Compression Tester with Spark Plug Tester, Automotive Engine Compression Tester
8PCS Compression Tester, Engine Compression Tester kit Pressure Gauge 0-300 PSI
