which shield have built in damage reduction?

or are all shields the same.. its just the look?

The inbuilt damage reduction is an add-on mod that shields can have - any type of shield can have this particular type of mod.

You'll notice that a bevvie of collector shields are all +x Health when enchanted/hexed & -x damage when enchanted/hexed.

The damage reduction isn't tied to any particular style of shield, it can be on any shield. So go grab a collector shield or run your luck on un-id'ed shields and see if you get the mod

thanks ^^