Problem: You are trying to test engine crank case pressure reading. Reaching into your toolbox, you grab your plastic crank case cap and twist it on. After twisting it five full turns, you realize the cap is not engaging to the valve cover. Come to find out, the plastic tabs that hold the crank case cap have broken off. Solution: Calling AGA Tools and adding our aluminum Crank Case Test Cap to your toolbox. With this Crank Case Test Cap, it is designed with high end components to not break. Benefit: With the AGA Tools Crank Case Test Cap, you are able to use our Test Cap with most early model vehicles to late model vehicles with steel, aluminum or plastic valve covers. The multi-diameter fitting on the Crank Case Test Cap will allow you to connect directly to an IMIBs, handheld Manometers and smoke machines. Not needing an adapter will prevent leaks and wrong readings.