It's a solar mod, right? Do you have any solar legendary legs?

Today, Banshee is selling a Fusion Rifle Scavenger mod, says 'Leg Armor Mod'.

However, after purchase, it doesn't show up as available on any Armor 2.0 legs EXCEPT exotics.

Huh?

It's showing up on a bunch of my boots for me.

Are you sure you're looking at stuff with the correct elemental affinity?

Just in case there's any confusion--each piece of armor randomly rolls with an "affinity" for one of the three Destiny elements. Your Fusion Rifle Scavenger mod has a solar affinity, and is a mod for leg armor. That means you can only apply that mod to boots that rolled as Solar affinity boots. If it's arc or void, you just can't use that mod on those boots.

So mods are locked both to which armor slot they go on and the elemental affinity they require. Unflinching Hand Cannon Aim for example is a void mod that can only go on chest pieces.

There's no way in the game to see what mods you have in total. The only way to see your mods is to inspect the piece of armor for each slot individually, and manually check armor that is either solar, arc, or void affinities.

This chart helps in that you can at least see which mods are which affinities and are equipped on which armor slot. There's still no way to tell if you have those mods other than inspecting the armor and seeing if you have it available.

So if I'm reading this right, ALL the mods that are relevant to any given weapon type will always be tied to one specific energy affinity? That makes things much simpler and wasn't at all apparent to me in-game.