Polymaker Filament Storage Box Edition II - Dry, Organized Filament

In this review the Polymaker PolyBox Edition II is judged as a practical, compact storage solution for hobbyists and small workshop users who need to keep filament dry and accessible. The single biggest reason to buy is the built-in high-precision thermo-hygrometer, which lets users monitor internal humidity and maintain levels below 15% to reduce moisture uptake during storage and printing. It is not a heated dryer, but it is engineered to be energy efficient and to work with reusable desiccant for ongoing filament protection.

Key Features

• Compact footprint: The box measures 31 x 18 x 23 cm without the base and 31 x 18 x 31 cm with the base, fitting on crowded workbenches without consuming much space.
• Flexible spool capacity: Supports either 2 x 1 kg spools (up to 52 mm width each) or a single 3 kg spool (up to 120 mm width), which covers most consumer and small-pro spool sizes.
• Built-in monitoring: The integrated thermo-hygrometer provides accurate humidity and temperature readings so users can keep humidity below 15% and protect filament quality.
• Dual slot design: Slots in both the base and the lid let users route filament for printing without removing the lid or to place the box lower than the printer as needed.
• Reusable desiccant: The supplied desiccant bag is reusable, reducing ongoing costs and waste while maintaining a dry interior environment.

Who It's For

The PolyBox Edition II is aimed at 3D printing hobbyists, makers, and small workshop users who want a reliable, compact solution to store filament from moisture exposure and to feed a printer during a print. It is especially useful when space is limited and when users want real-time visibility into humidity conditions via the thermo-hygrometer.

Users who need active heating or rapid drying cycles should look elsewhere, since this box contains no electric heating elements and is designed for passive humidity control with desiccant. Large production environments relying on many spools or integrated drying systems may also require a bigger, heated solution.

Pros & Cons

Pros

• Integrated hygrometer gives clear humidity and temperature feedback to protect filament.
• Flexible capacity supports two 1 kg spools or a single 3 kg spool for versatile use.
• Dual slot design lets users route filament without interrupting prints or reposition the box relative to the printer.
• Reusable desiccant reduces replacement costs and simplifies ongoing maintenance.

Cons

• Not a heated dryer; it relies on desiccant and passive control, so it will not actively remove heavy moisture.
• Some customers report mixed feedback on build quality and setup, so handling carefully during assembly is advisable.

Specifications

Dimensions (without base)	31 x 18 x 23 cm
Dimensions (with base)	31 x 18 x 31 cm
Supported spools	2 x 1 kg (max 52 mm width each) or 1 x 3 kg (max 120 mm width)
Humidity control	Built-in thermo-hygrometer; maintain below 15%
Desiccant	Reusable desiccant bag included
Slots	Slots in base and lid for filament routing

Our Verdict

The PolyBox Edition II is a solid value for hobbyists and small shops that need compact, monitored filament storage without active heating. With a clear thermo-hygrometer, reusable desiccant, and flexible spool accommodation, it protects filament from moisture and supports uninterrupted printing. Buyers wanting an active drying solution or a larger industrial cabinet should consider other options, but for most desktop setups this box balances size, monitoring, and cost effectively.

Frequently Asked Questions

Does the box heat filament to dry it?
No. The PolyBox Edition II contains no electric heating elements and is designed for passive moisture control using desiccant.

How many spools can it hold?
It holds either two 1 kg spools with a maximum width of 52 mm each, or a single 3 kg spool with a maximum width of 120 mm.

Can I route filament without removing the lid?
Yes. The box has slots in both the base and the lid so filament can be routed for printing without interrupting a print or to place the box lower than the printer.