## Common ground
All are radiator humidifiers—devices that add moisture to air by evaporating water using heat from a radiator.
## Options at a glance
**3924.90 – Plastic material**
- **Defining trait:** Constructed primarily from plastic, which is lightweight and cost-effective.
- **Typical examples:** Household humidifiers with plastic trays or tanks.
- **Best fit when:** You need an affordable, lightweight option for general home use.
**6914 – Ceramic material**
- **Defining trait:** Made of ceramic, offering better heat retention and durability.
- **Typical examples:** High-end humidifiers with ceramic heating elements or evaporative pads.
- **Best fit when:** You prioritize longevity, even heat distribution, or a premium build.
## Key differences
| Feature | 3924.90 (Plastic) | 6914 (Ceramic) |
|------------------|-------------------|----------------|
| Material | Plastic | Ceramic |
| Heat retention | Low | High |
| Durability | Moderate | High |
| Cost | Lower | Higher |
## How to choose
- Is the humidifier made of lightweight, low-cost material? → 3924.90
- Does it use ceramic for better heat stability and longer life? → 6914
## Overlaps & pitfalls
A humidifier may combine both materials (e.g., plastic housing with ceramic heating element), but the HS Code depends on the *primary material* of the main functional part. If unclear, prioritize based on the **main structural or heat-exchange component**. The label "ceramic" suggests it’s a defining feature; otherwise, assume plastic unless specified