This ring has up to 10 charges. While wearing this ring, each time you hit an enemy with an unarmed strike the ring gains 1 charge. You can use an action to expend 5 charges to regain 1 ki point. 

The ring gains power based upon the wearer's monk level.

Level 3: +1 to damage rolls with monk weapons and unarmed strikes.

Level 6: When you hit with an attack with a monk weapon or unarmed strike, you can expend 5 charges to deal extra damage equal to your Martial Arts die. You can use this feature only once on each of your turns. 

Level 11: Increase the number of maximum charges to 15. In addition, the number of ki points gained when you expend 5 charges increases to 2. 

Level 15: +2 to damage rolls with monk weapons and unarmed strikes

Level 20: +3 to damage rolls with monk weapons and unarmed strikes. In addition, you can expend 5 charges to deal extra damage equal to your Martial Arts die up to two times on each of your turns.

Notes: monk