They are pure mandarin, probably satsuma.
They are poor bearer when young but it changes few years later.
We didn't find the limit to their cold hardiness.
They are seedless,
The fruits of the first flowers (they set flowers at least twice a year) are ripe before the first true colds.
I see only one cons, the tree is very bushy and thorny. It makes the harvest painful.
This plant is the revolution we were waiting for more than a century.
It pushes the culture limit one thousand kilometre north!!!