The effect of the Holy wrench is restoring an additional 2% of the player's Prayer points when the player drinks a dose of any prayer restore potion. This means that each dose of the potion will restore 27% of your prayer on top of the base restore of 7, 8, or 9, instead of 25%. All numbers are rounded down to the closest integer as usual. The Holy Wrench does not provide any prayer bonus. Listed below is the gain per dose of potion when using a holy wrench at different levels.