Why doesn The Zapper have the option to work off a Wall Adaptor?
Several reasons: 1) The specifications do not call for it. 2) The battery lasts for months, so there really is no need to offer this. 3) There would have to be conditioning circuitry in the unit to smooth out any of the 60 Hz line frequency so it would not interfere with the pure 30 kHz output. This is VERY important! The cost of the Zapper would go up as a result. 4) Liability issues.