Telsa armour??

[T'rissirahc]

what is that, and ev. where can it be found??

[Mr. Pastorius]

First of all, it's called a Tesla armor, named after a Serbian-Croatian scientist, so searching the site for a "Telsa armor" won't give you any useful information.
Now, the Tesla armor is... a type of armor.
Ok, seriously, it's an armor capable of stopping slightly more energy based damage than the Power Armor, but its kinetic and heat defence capabilities are those of a metal armor. To keep it simple: good against plasma/laser/pulse, not very good against bullets/flame/explosives. Therefore, for most combat situations the Power Armor is a better choice, unless you're wiping out Navarro.
EDIT: Oh, right, I forgot to say where to get it. As far as I can recall, you can only buy it in the first two shops in San Francisco.

[T'rissirahc]

Wow, thanks Mr. Pastorious appreciate your help and admire your knowledge