These adapters allow you to reuse your existing wiring and connectors to a battery with different terminals.
The Converted Terminal Adapter converts either a NB (nut and bolt) terminal or an IT (internal thread) terminal on the battery to F2 (.25") terminal for your existing connector. The opening of the adapter accepts an M5 bolt, and provides a male F2 terminal for your connector to attach to.
One quantity of this item comes with a pair of adapters. If you have one battery, you'll want one Converted Terminal Adapter.