Question about a certain collectors bow

Hey everyone,
I got a bow for my new ranger char, and got a collectors bow:

Shocking Diessa Flatbow
Lightning damage: 11-18 req. 3 Marksmanship
Damage +15% (while Health is above 50%)
Armor penetration +10% (Chance: 10%)

If I was to add a 10/10 sundering string, would it stack? (I dont want to add a sundering string, specially not 10/10, just wondering)

~HD

No, It would remove the shocking prefix.

EDIT: I get what your asking now. And yea, you'd have 2 10% chances at sundering damage...Useless to do that thouygh.

So wouldnt two instances of sundering 10/10 be sundering 20/20 (20% armor penetration, 20% chance)?

no, it'd be more along the lines of
Sundering 10% chance 20%
AND Sundering 20% chance 1%(i think... It's too late for me to do maths)