rings in treasure

I can't se topic,, sow I try again
Under the "Treasure" I have a lot of rings in different levels, - what can these be used for and how?

Rings increase your fortune level
To equip the ring - tap the ring, then tap "equip"
It will now appear in the "general" UI

You will see a +# # - being an interger, max of 10 as the max ring is level 10

the higher the level, the more fortune the ring gives

the other rings may be sold for money, either to the computer(by clicking on the item and hitting "sell to NPC") or in market by going to market building, clicking sell, and choosing the ring, and setting your price.

Sorry but I am confused.
Press my Treasure icon, I have a book, a level 1 ring, a level 3 ring, a level 8 ring, and a level 2 ring.
I pressed "Equip"on my level 3 ring, it becomes changed to a level 5 ring??

I look under the "General" I have a level 1 ring ... I pressed the "Treasure"on my level 8 ring, it goes over the "General"as a level 8?

What is the logic in this?

and How do I make en level 9 ring ?

another thing. Under "Treasure" I have level 1 book, if I press on this I get this messages "Treasure has been equipped yet.. ??
How can I equip the book ?

you cannot combine or make items. . .of your rings just equip the level 8 one, you can only equip one at a time so the lower level rings are useless, better to sell them for gold O.o

as for your manual, you must only have 1 of them, and you cannot combine them. the manual is already equipped, as it is telling you.