Which of the following is true regarding First-Class mail pieces?

The statement that First-Class mail pieces become Priority Mail at 13.01 oz is accurate because of the United States Postal Service's guidelines. First-Class Mail is designed for letters, postcards, and small packages, with a weight limit that typically caps at 13 oz. However, when a mail piece exceeds this weight limit, it transitions into a different service category, specifically Priority Mail, which can accommodate heavier items and offers additional benefits such as faster delivery and tracking options.

First-Class Mail serves as a cost-effective way to send lightweight items domestically, and understanding this transition at the 13.01 oz mark is crucial for customers who want to select the appropriate mailing service based on their needs. Mail pieces that are heavier than the First-Class limit must be sent as Priority Mail. This distinction helps businesses and individuals select the right service for their mailing requirements based on weight and delivery time expectations.

The other options presented do not align with the characteristics of First-Class mail. There are specific weight limits (not all pieces must be over 1 oz), size and weight are not unlimited (there are maximum thresholds), and international mail can be sent through various categories including First-Class and Priority. Thus, the confirmed correct answer emphasizes a significant aspect of how these mail