I took a look at class mods at http://borderlands.wikia.com/wiki/Borderlands_Wiki, and had a question about loyalty. 

Gunfighter (Jakobs Loyalty)	+28% - +61% Weapon Damage	Gun Crazy	Focus	Deadly	+84% Weapon Accuracy	+56% Weapon Reload Speed

 They're special gun mods, really rare to find, sometimes in treasure chests, they'll drop randomly like most loot
Dunno if this is still the case, but when the DLC first came out there was a problem where the game would think the mods were fake and delete them the moment you logged off
 

" @Glak: I understand that they're rare. I'm asking about LOYALTY. "

Ah
Basically it means that you can only use the guns that the loyalty mod indicates to be able to benefit from the  effects
So take that gunman mod for example, it's made by S&S so you can only use S&S guns for it to work

" @Axxol said:

" @Glak: I understand that they're rare. I'm asking about LOYALTY. "

Are you retarded? he answered your question. "

" Ah Basically it means that you can only use the guns that the loyalty mod indicates to be able to benefit from the  effects So take that gunman mod for example, it's made by S&S so you can only use S&S guns for it to work "

" @Glak said:

" Ah Basically it means that you can only use the guns that the loyalty mod indicates to be able to benefit from the  effects So take that gunman mod for example, it's made by S&S so you can only use S&S guns for it to work "

Okay, thanks.  Have you ran into anyone with these class mods? "

" @Glak:  @dudeglove: I just soloed Crawmerax and I found one of the Mods. It's the S&S Loyalty Gunman Mod. I can still use other weapons, the mod only gives the attributes to the S&S weapons.  "

" @Axxol said:

" @Glak:  @dudeglove: I just soloed Crawmerax and I found one of the Mods. It's the S&S Loyalty Gunman Mod. I can still use other weapons, the mod only gives the attributes to the S&S weapons.  "

Yup, that's what I meant Nice job dude, gratz on the mod Does it still dissapear after you stop playing, or did they fix it? "

" @Glak said:

" @Axxol said:

" @Glak:  @dudeglove: I just soloed Crawmerax and I found one of the Mods. It's the S&S Loyalty Gunman Mod. I can still use other weapons, the mod only gives the attributes to the S&S weapons.  "

Yup, that's what I meant Nice job dude, gratz on the mod Does it still dissapear after you stop playing, or did they fix it? "

Nope, they didn't fix it; the mod is gone now. "