Shipping profile
The setting on a listing that tells Whatnot an item's packed weight, and sometimes its dimensions, so shipping can be priced, labelled and bundled.
A shipping profile is what you choose on every listing to tell Whatnot how the item ships. It carries the item's packed weight, meaning the item plus the box or mailer plus any packaging materials, and in some cases its dimensions. Whatnot uses that to work out what the buyer pays at checkout, which shipping services are available, how the label is generated after the sale, and how separate wins get combined into one shipment.
Most listings use one of the suggested profiles, which are the standard weight brackets. A custom profile exists for items that need more control over how they ship or how they bundle. The bracket a suggested profile represents is what sellers usually call the weight class, so the two words describe different parts of the same decision: the profile is the setting on the listing, the class is the tier it falls into.
Accuracy cuts both ways, and this is the part that costs money. Understate the packed weight and the label can come out underpaid, which means adjusting the shipment after the sale, covering the difference yourself, or having the carrier refuse the package. Overstate it and buyers pay more to receive your items than they need to, which quietly makes you look expensive next to a seller listing the same thing honestly. Weigh your common item types once, packaging included, and the guesswork stops.