Antenna Yagi Extreme 3 Dual Driven

By Jeriyant,
Hello Friends, can you explain what type of this yagi antenna is? in my country this antenna is very popular and good, because it has high gain and in areas with no signal at all you can get 3G and 4G LTE signals. I hope my friends can explain this antenna, because I have tried to do a yagi calculator but nothing fits this type of antenna.