Compression Gauge Test Set for Engine Cylinders Diagnostic Tester with 5 Adapters M10 M12 M14 M16 M18 5 Adapters for a wide number of vehicles (spark plug types/depths) includes rare M16 adapter not available in comparable kits Kit includes 2 rubber cones ends for quick check (no need to thread into head) 3" Gauge has dual color scale with 0-300 PSI, 0-20 kPa Fittings: M10, M12, M14, M16, M18 (Male, With O Ring) Includes 10mm, 12mm, 14mm, 16mm and 18mm spark plug adapters