Prusa USS Drybox

Current lead time approx 5 to 6 weeks

Wet filament = ruined prints

When wet filament hits the hot nozzle, the water inside instantly boils, expanding in volume. This creates steam bubbles that pop out of the nozzle, leading to stringing, oozing, and rough finish instead of smooth walls.

Never deal with wet filament again.

Most filament storage boxes are just repurposed food containers. We built the Prusa USS Drybox from the ground up for 3D printing, made from special hydrophobic materials. It's a sealed storage container built around a simple idea: place your spool inside, print directly from the box, and leave it there until it’s empty.

Unique quick access port

Access and load your filament without opening the lid. The sealed port keeps moisture out while you print, and it fits a PTFE tube perfectly for direct connection.

Universal Mounting

A clever central opening allows the box to mount directly onto your existing spool holder (the Prusa bayonet spoolholder). This way, we also minimized the free internal space where humid air could accumulate.

Stackable Design

The flat sides make the boxes fully stackable for neat organization. One box per spool: place it inside once, and leave it there until the roll is empty.

Fits the vast majority of spools

We made the box big enough to fit standard spools from just about any brand (up to 1kg), along with smaller specialty rolls.

Key benchmarks

Why you should choose the Prusa USS Drybox

95% less moisture absorption vs. ambient air

5 × more airtight vs. generic dryboxes, on par with Museum-Grade Sealing

50% better sealing vs. generic dryboxes

Stable for weeks

10% Relative humidity when using 50g silica gel

Museum‑Grade Sealing

Apart from measuring moisture absorption over time, Prusa also measured the airtightness with CO2 Decay method. By tracking how fast tracer gas escapes, Prusa calculate the Air Exchange Rate (AER). Where a basic zip-lock bag had AER of 5.40 and a generic drybox 0.74, the Prusa USS Drybox achieved AER of 0.15, which is extremely low. To put that in perspective, that level of airtightness is typically only required for museum display cases used to preserve fragile historical artifacts.

Useful features

Integrated Sensor

Always know the exact conditions inside. Built-in hygrometer and thermometer for easy monitoring (°C/°F).

Label Holder

Identify your materials easily with included tear-off labels or 3D print your own custom tags, using a template from Printables.com.

Smart Side Access

Small side covers let you manually rotate the spool or replace silica gel without opening the whole box.

Common Questions

Which spoolholders are supported?

The Prusa USS Drybox fits perfectly on the bayonet style spoolholder found on the Prusa CORE One+ and CORE One L. For CORE One, XL, MK4/S/+ and HT90, we provide printable adapters (soon on Printables).

Can I print directly from it?

Yes. The sealed PTFE exit port allows your printer to pull filament with low friction while keeping the internal environment airtight.

Does it come with desiccant?

It includes space for 50g of silica gel, which maintains 10% relative humidity (RH) for weeks at a time.Will this work with my non-Prusa printer?

Will this work with my non-Prusa printer?

You can feed filament directly from the box to any 3D printer. Attaching the drybox on the printer will work with compatible spoolholders, such as those on Prusa 3D pritners (spoolholder with bayonet lock system), or any community made spoolholders for other printers.