Prosthetics are usually metal and custom made to replace whatever portion of a limb has been lost.

While you are standing on your prosthetic, you cannot gain advantage or expertise dice on saving throws made to resist being knocked prone, and you take half damage from caltrops, spikes, and difficult terrain that deals damage. Depending on how your prosthetic is constructed, you can use it to store up to one concealed Tiny item (DC 15 Investigation or Perception check to notice).

Prosthetics are usually metal and custom made to replace whatever portion of a limb has been lost.

You cannot gain advantage or expertise dice on Sleight of Hand checks made with this prosthetic. However, prosthetics can provide an unexpected block, and when you use it defensively you gain a +1 bonus to your AC as if you were wielding a hands-free light shield with the prosthetic. Prosthetics used defensively in this way cannot wield weapons.

Prosthetic hook hands are common replacements for missing hands. You cannot gain advantage or expertise dice on Sleight of Hand checks made with a hook hand. In addition, a hook is a natural weapon which you can use to make unarmed strikes that deal piercing damage equal to 1d6 + your Strength modifier.