Powertech "Shoulder Cannon"?

[Soulfinger]

I hit level 51 on my Powertech (Merc Tank) the other day, and was choosing my advanced skills. One that sounded good was this:

Shield Cannon – Shoulder cannon missiles heal you for 5% of total heath

Damage and self-healing sounded like a good thing, and it was recommended in every build.

My problem: WTH is "Shoulder Cannon"? I can find no ability or skill called Shoulder Cannon. It's not in my list of abilities, and it is not in my skill tree. I also can't find it on the Skill list, although it it is mentioned as the last skill to use in a rotation in the Duffy guide.

I'm sure I'm missing something... but is this skill referred to something else in the actual abilities?

[Windemere]

I realize this is in the category of "did you remember to plug it in?", but you did see your trainer after hitting 51, right? It should be a level 51 powertech ability that you get after you train at that level.

[Soulfinger]

Ahhh... thanks. I did not hit the trainer, so that must be it... I thought you either got a new ability -OR- got one of the selectable buffs.

Will hit the trainer asap.

[Windemere]

Great, enjoy. It's awesome in PvP for node guarding.