## Common ground
All options are types of heating (or cooling) pads used for therapeutic or comfort purposes.
## Options at a glance
**1204.00 – Linseed-filled pads**
- **Defining trait:** Heated by external sources (e.g., microwave), not electric; filled with linseed.
- **Typical examples:** Microwaveable linseed heating pads for back pain.
- **Best fit when:** Non-electric, reusable, natural filler (linseed) is key.
**1404.90 – Aromatic plant-filled pads**
- **Defining trait:** Filled with aromatic or herbal materials (e.g., lavender, chamomile), non-electric.
- **Typical examples:** Herbal heat packs for relaxation or cold therapy.
- **Best fit when:** Natural, scented fillers are the main feature; no electricity used.
**8516.79 – Electric seat pads**
- **Defining trait:** Electrically heated, designed specifically for seating (e.g., car seats).
- **Typical examples:** Car seat heating pads with built-in electric elements.
- **Best fit when:** Used in vehicles or for seated comfort; electric and fixed to a seat.
**8516.79 – Infrared heating pads**
- **Defining trait:** Use infrared radiation (non-contact heat); electrically powered.
- **Typical examples:** Infrared therapy mats or wraps for muscle relief.
- **Best fit when:** Heat is delivered via infrared waves; often used in physiotherapy.
**8545.90 – Automotive PTC heater pads**
- **Defining trait:** Use PTC (Positive Temperature Coefficient) carbon-based paste for self-regulating heat; designed for vehicles.
- **Typical examples:** Car seat or steering wheel heating pads with automatic temperature control.
- **Best fit when:** Self-regulating, vehicle-specific, and uses PTC technology.
**9018.90 – Disposable therapy pads**
- **Defining trait:** Single-use, medical-grade pads for heat/cold therapy in clinical settings.
- **Typical examples:** Hospital-used disposable heating or cooling packs.
- **Best fit when:** Used once and discarded; intended for clinical or sterile environments.
## Key differences
| Option | Power Source | Fill Material | Reusability | Primary Use Case |
|-------|--------------|----------------|-------------|------------------|
| 1204.00 | External heat | Linseed | Reusable | Home therapy |
| 1404.90 | None | Aromatic plants | Reusable | Relaxation |
| 8516.79 (seat) | Electric | N/A | Reusable | Car seat comfort |
| 8516.79 (infrared) | Electric | N/A | Reusable | Therapy |
| 8545.90 | Electric (PTC) | Carbon paste | Reusable | Automotive |
| 9018.90 | None | Chemical/absorbent | Disposable | Clinical use |
## How to choose
- Is it electric? → Yes: go to 8516.79 or 8545.90
- Is it for a car seat? → Yes: 8516.79 (seat) or 8545.90
- Does it use infrared heat? → Yes: 8516.79 (infrared)
- Is it filled with linseed? → Yes: 1204.00
- Is it filled with herbs or plants? → Yes: 1404.90
- Is it disposable and used in clinics? → Yes: 9018.90
## Overlaps & pitfalls
- **8516.79** appears twice: one for seat pads, one for infrared. These are distinct by function (use case vs. heating method). Choose based on *purpose* (seating vs. therapy) or *technology*.
- **Non-electric vs. electric**: Clear split; avoid confusion between reusable and disposable.
- **"Pad" vs. "cushion/pillow"**: All are flexible, but 8516.79 covers broader forms.
- If multiple traits apply (e.g., electric + infrared), prioritize the *main function* or *technology*. No priority rule given—user must decide based on product’s primary feature