Will China Cell Phone Jammer have bad effect to human body? 

You need not worry about whether the Cell Phone Jammer is harmful for your health. Since the intensity of the electromagnetic signal sent by the Cell Phone Jammer is within the criteria of environmental protection. The signal sent by Cell Phone Jammer is not big enough to cause damage to human. 

The Cell Phone Jammer is just sending signals to block the use of cell phones, as a result, it is not bad for human.
After all, just as the use of Cell Phone, the same principle is available for the usage of Cell Phone Jammer. Anyway, if you use proper, those electronic devices, including Cell Phone Jammer will be made use of to largest extent.

Moreover, even though you keep the jammer working long-time, it would not damage the Cell Phone Jammer itself because We are thinking of taking use of the conductivity of metal shell to help the heat sinking during our designation. By this way,the machine can be kept in good working condition for long time.
Well, the premise should also be that you take good care of the Cell Phone Jammer and put it in good use rather that just damage the Cell Phone Jammer.

Another point worth to mention is that the the working distance is the most concerned point for the buyers. Usually, the distance is 10 m to 1km. Sometimes it ranges according to places. For example, the working range of the professional Cell Phone Jammers on the highway is 1000m, while it is 500m in the center of city.

At last, all of our China Cell Phone Jammers are made in China factories, with high quality and proper acceptable prices. If you have any questions, feel free to contact with us forever, we will always be happy to serve for you all.