Guarantee of bond
Guarantees that a Contractor bidding for a contract will, if the bid is accepted, enter into a contract and furnish all bonds required to complete the project including performance, payment and maintenance bonds. Or, if the Contractor refuses to enter into a contract, the surety will pay you the difference between the amount of the bid and the bid finally accepted.
Can protect the state if the Contractor makes a mistake in bidding the project. If the Contractor leaves out an important portion of the project in the bid, and the bid is subsequently accepted, the surety would be obligated to pay the difference between what was bid and the actual cost to complete the project.