While this item is on your persons you have an extra spell slot of the highest level you currently have -2.

As an action or reaction, you may take this item from your persons and flip it upside down. Doing so will cause you to become ethereal as well as frozen in place, unable to move or take any actions, bonus actions, or reactions for a full round of combat. You have full awareness of your surroundings during the effect. You can only use this item once per day and it will recharge at dawn if the conditions are met.

Roll 1d8 on each use: on a critical fail the hourglass shatters and is destroyed. On a critical success the hourglass is instantly recharged and may ignore the once per day rule for that charge. On any other number nothing happens.