You may want to review the following:
The ParaZapper UZI series have Pedestal Offset that is better than just Positive offset.
They also offer a true square wave with a very accurate 50 percent duty cycle
The ParaZapper UZI series has a 10.5 volt output without using unsafe wall adapters.
The frequencies are also very accurate when compared to obsolete zappers such as the Ultimate Zapper
The UZI and UZI-2 offer 6 modes of operation and a total of 23 frequencies, while
The UZI-3 offers 8 modes of operation with a total of 41 frequencies.
The UZI is made with quality components on a high quality circuit board and rugged construction.
ParaZapper MY, UZI-3, and CC-2 as well as other ParaZapper zappers are now available at http://huldaclarkparazapper.com .
Some of my other posts:
Chikungunya - Still spreading across the Carribean and to the US