This is an electronic drum machine that has the tester lead not drumsticks. It generates beep sound when the sticks of red and black touch the conductor (e.g. the substance that conducts electricity). ... After that? No further explanation is necessary.
It is the tester, but...?
The Tester Drums can be used in the way as a typical electric tester. It can also be used to check the guitar cable, or the battery level of guitar effects. The tester is may be a sober, but an important tool to support your performance. How wonderful would it be if you could take the tester to the stage? The red and black sticks will surely stand out. Beat the best rhythm.