Uline S-16721 Equivalent: 12 x 3 x 3" Long Boxes (25-pack)
Model-to-size mapping verified against Uline’s published catalog listings on July 31, 2026; the Packrift price below is our live catalog price.
Uline model S-16721 is a 12 x 3 x 3" long box per Uline’s published listings. The Packrift exact-size equivalent — same length × width × height, same grade class — is 12x3x3 Shipping Boxes — ECT-32 Kraft Corrugated, 25-Pack, priced at $21.80 per 25-pack ($0.87 per box) today.
| Size | Grade class | Pack | Price today | Per box | |
|---|---|---|---|---|---|
| Uline S-16721 | 12 x 3 x 3" | Long Box | see your invoice | see your invoice | — |
| Packrift equivalent | 12 x 3 x 3" | Long Box | 25 | $21.80 | $0.87/box |
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Frequently asked questions
Is this the same box as Uline S-16721?
It matches S-16721’s published dimensions (12 x 3 x 3") in the same grade class, so it packs and stacks the same. It is not manufactured by or affiliated with Uline — when replacing a certified spec, match the certificate stamp printed on the box.
What if my Uline model isn’t listed here?
The cross-reference currently covers 634 verified models across boxes and mailers. Enter yours in the lookup tool, or request a quote with the model number and we’ll match it by spec.
Uline is a registered trademark of Uline, Inc. Packrift is not affiliated with Uline; model numbers are referenced for size-compatibility comparison only.