The Super Magnet is one of the two universal items. The second one is a special version of it the Experimental Super Magnet.
An activated Super Magnet will last for 5 charges or 1 hour whatever comes first. Each one will ad 300 meter to the current collection radius of all resources.
Every time you collect resources or capture a source via Capture or Collect one charge will be used. If a capture or collect wont lead to collecting resources or unlocking a Station no charges will be used.