Ring of teleport control
Evoking a ring of teleport control allows its wearer to gain the teleport control status effect. This will give you near-perfect control over your destination when teleporting and partial control over your blinks, but the intrinsic fades after each use. Also, controlled teleports take slightly longer than normal to kick in. The chance of successfully evoking this ring rises with your Evocations skill:
As this ring provides no combat bonuses and you generally won't be teleporting very often, you likely won't want to wear this at all times. That being said, it can be tremendously useful when coupled with a scroll of magic mapping for entering heavily guarded vaults without actually dealing with the guards, or when attempting to bypass inconveniently placed teleport traps. Even with no Evocations skill, it can be reliably evoked after a few tries. Just be aware that it will not function in areas with -cTele.
Prior to 0.13, this ring passively granted its intrinsic for as long as you wore it.