Ancestry
You have a hollow storage cavity inside one forearm.
You can hide a small object of up to light Bulk inside this compartment.
It takes 3 Interact actions to store an object inside (representing opening the panel, seating the item, and sealing it).
You gain a +4 circumstance bonus to the DC of checks for others to Seek or Steal objects stored in your arm.
If you store a weapon inside, you can use a single action to Interact to draw the weapon into the matching hand and then Strike with it (draw + Strike as one action).