Instant Bridge

This thin steel plate is approximately 1 foot square. When the command word is spoken, it rapidly stretches outward and unfolds, becoming a panel 1 inch thick, 3 feet wide, and up to 30 feet long (stopping its extension when it encounters any resistance, such as a wall, ceiling, or a creature.) Each 5-foot segment of the metal bridge has hardness 10 and 30 hit points. The bridge weighs 300 pounds and can support up to 4,000 pounds. When the command word is repeated, it collapses into its portable form once more.

The instant bridge can be activated up to three times per day. If any part of it destroyed while it is extended, it immediately loses all magic.