I needed something to increase efficiency because cell phone use reduced productivity. It starts working three seconds after turning it on. The phone shows no signs of loss of signal or malfunction. The user therefore assumes that this is a service rendered. Magic!
Works normally, has been used for two months, and the effect is pretty good.
I used to buy a cell phone signal jammer, and the signal shielding effect is good. I bought it again this time, hoping not to let me down.