The shield appears as a normal +1 shield, but with odd runes and lines in Primordial that appear to be a spell. The spell cannot be cast or transferred to a spellbook, as it is specific to the shield. 

As an action, or a bonus action while wielding a magic one-handed ranged weapon (such as a firearm or handcrossbow) the user can summon a small barrier. The barrier acts as half cover for medium creatures, and 3/4 cover for small creatures. The shield is 4 ft tall and 10 ft wide 

This barrier last for 2 rounds and gives advantage on ranged attacks made while behind the barrier. This applies to allies of the user. 

Shields require the Utilize action to Don or Doff. You gain the Armor Class benefit of a Shield only if you have training with it.

Notes: Bonus: Armor Class, Spending a long rest wielding the shield with any finnese one handed weapon (short rest if wielding with a magic weapon or if by an artificer) , Combat, Warding