With your lower legs bound in gossamer silk, you become ephemeral, and sometimes invisible.
Feet Slot 85,000 gp
if you move at least 3 squares on your turn, gain concealment until the end of your next turn.
Power (Illusion) Daily (Free Action)
Use this power when you have moved at least 6 squares on your turn. You become invisible until the end of your next turn.
Published in Adventurer's Vault, page(s) 129.