Where to find serration mod?

[Ztealthy]

Im new and i want to get the undamaged serration mod for my boltor. Can someone help me?

[THER]

Dropped by

Missions:
Excavation (T1, T2, T3)
Interception (T1, T2)
Survival (DS1, DS2, DS3, T1, T2, T3)
Spy (Lua, T1, T2)
Defense (DS) <- this is your best bet. Eris>Akkad

Enemies:
Electric Crawler (0.17%)
Kuva Scorpion (0.22%)
Nauseous Crawler (0.33%)
Scorpion (0.22%)

Other:
Orokin Tower Containers

EDIT: (DS) = Dark Sector

[Blackcompany]

BlackCoMerc in game.

If I am on, look me up. I will give you one of almost any of the core mods you want, without asking for anything in return. I cant use them and they help alleviate the grind for mods you should be given as part of the tutorial.