Priest · Discipline · tier 2 · from level 15
Improved Power Word: Shield
+186 Power Word: Shield
3/3 · level 60 · per cast
Improved Power Word: Shield
Rank 3/3
Increases the damage absorbed by your Power Word: Shield by 20%.
Averages, counting crits and misses, for a level 60 Priest with a typical weapon and no other gear or buffs, against a target your level. Worked out from the game's own data, the same way as the Foresight addon.