Prusa USS Drybox

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. 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. We made the box big enough to fit standard spools from just about any brand (up to 1kg), along with smaller specialty rolls. The box includes space for 50g of silica gel, which maintains 10% relative humidity (RH) for weeks at a time. Integrated Sensor - Always know the exact conditions inside. Built-in hygrometer and thermometer for easy monitoring (°C/°F). Smart Side Access - Small side covers let you manually rotate the spool or replace silica gel without opening the whole box. Label Holder - Identify your materials easily with included tear-off labels or 3D print your own custom tags, using a template from Printables.com. 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.

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.Most filament storage boxes are just repurposed food containers. Prusa 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.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.A clever central opening allows the box to mount directly onto your existing spool holder (the Prusa bayonet spoolholder). This way, Prusa also minimized the free internal space where humid air could accumulate.The box is big enough to fit standard spools from just about any brand (up to 1kg), along with smaller specialty rolls.