Lightweight battery terminal covers are color coded for easy identification of a polarity. Protect the top posts on your battery from accidental shorts and inadvertent contact.
The positive terminal MUST be insulated (on negative ground systems). The negative terminal is optional and can be left uninsulated, but can be covered also. If your car does not already have a terminal boot to cover the positive terminal, or your terminal cover/boot is worn, this set can protect your battery terminals.