What is it

The oversized price is used on parcels of certain mail classes that are greater than 108 inches, but not more than 130 inches, in combined length and girth. Weight is not a factor as long as it does not exceed 70 pounds (no package can exceed 70 pounds).

Carrier Source

https://faq.usps.com/s/article/What-are-the-Different-Ways-Parcels-are-Priced

What you will be billed

$100

Will it apply to my shipment?

Parcel Select (Parcel Select Lightweight excluded)Parcel Return ServiceUSPS Retail Ground®USPS Retail Ground® -- Limited Overland Routes parcels