Hunter · Marksmanship · tier 4 · from level 25
Improved Serpent Sting
+52.7 Serpent Sting
5/5 · level 60 · per cast
Improved Serpent Sting
Rank 5/5
Increases the damage done by your Serpent Sting by 10%.
Averages, counting crits and misses, for a level 60 Hunter 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.