The Tokkul-Zo is a quest reward worn in the ring slot from the quest, The Elder Kiln.
Upon receiving it, it holds 3,000 charges. While charged, the player receive a 10% damage bonus when fighting lava or obsidian creatures. This damage bonus does stack with the bonus of the Slayer helm and the Full slayer helm.
Once all the charges have been used up, it can be recharged by TzHaar-Mej-Ak or TzHaar-Mej-Jeh in the TzHaar City Main Plaza for a fee of 48,000 TokKul (16 per missing charge).
The ring can be used to get to, and teleport around the TzHaar city. Teleports include the Main Plaza, Fight Cave, Fight Pits, and the Fight Kiln. Teleporting does not uses up charges, only when you are attacking obsidian creatures.
Note that when the Tokkul-Zo has depleted its 3,000 charges, it no longer has combat bonuses, or the ability to teleport.
If lost, the ring can be reclaimed by speaking with TzHaar-Mej-Ak or TzHaar-Mej-Jeh. However, the ring will be uncharged, meaning it will no longer have combat bonuses, or the ability to teleport.