1. Introduction
This instruction manual provides essential information for the proper use and maintenance of your HARIO Coffee Scale Polaris Silicone Cover (Model: C-CST-B). This product is designed to protect your HARIO Coffee Scale Polaris (Model: CST-2000) and facilitate easier cleaning during coffee preparation. Please read this manual thoroughly before use and retain it for future reference.
2. Product Overview
The HARIO Coffee Scale Polaris Silicone Cover is a protective accessory made from silicone rubber. It is specifically designed to fit the HARIO Coffee Scale Polaris (CST-2000) to prevent scratches and simplify the cleaning process. Its angled design also assists in weighing with an espresso portafilter.

Image 1: The HARIO Coffee Scale Polaris Silicone Cover (C-CST-B) in black.

Image 2: Illustration showing how to place the silicone cover onto the Polaris coffee scale. The Polaris scale is not included with this cover.
3. Setup
The silicone cover is designed for simple placement on your HARIO Coffee Scale Polaris (CST-2000).
- Ensure your HARIO Coffee Scale Polaris (CST-2000) is clean and dry.
- Carefully align the silicone cover with the top surface of the scale.
- Gently place the cover onto the scale, ensuring it sits flat and securely. The angled edge should align with the front of the scale for optimal use with portafilters.

Image 3: A portafilter placed on the covered Polaris scale, demonstrating how the cover facilitates espresso weighing.

Image 4: A coffee dripper and server on the covered Polaris scale, illustrating protection from daily use and spills.
4. Operating Instructions
The silicone cover enhances the functionality and protection of your HARIO Coffee Scale Polaris. It does not alter the scale's operation but provides a protective and easy-to-clean surface.
4.1 General Use
- Place the silicone cover on your Polaris scale before use.
- The cover protects the scale from scratches and spills during weighing.
- The angled design is particularly useful for stabilizing portafilters during espresso preparation, allowing for accurate measurement of coffee grounds.
4.2 Scale Operation with Cover
Operate your HARIO Coffee Scale Polaris as usual. The cover is thin enough not to interfere with the scale's accuracy or touch-sensitive buttons.

Image 5: The Polaris scale with the cover, highlighting its ability to display the amount of hot water to pour and the extraction progress.
4.3 Button Interaction
The cover is designed to allow full functionality of the scale's touch buttons.

Image 6: Pressing the 'on/off tare' button to power on/off or tare the scale.

Image 7: Pressing the 'time mode' button to switch modes.

Image 8: The timer display in a blinking state, indicating readiness or a specific mode.

Image 9: The timer starting automatically during operation.

Image 10: Illustration of switching between Classic Mode and Polaris Mode by pressing the 'time mode' button.
5. Maintenance and Cleaning
The silicone cover is designed for easy cleaning, helping to maintain hygiene and prolong the life of your coffee scale.
- After each use, especially if coffee powder or liquid spills occur, remove the silicone cover from the scale.
- Wash the cover under running water. Mild dish soap can be used if necessary.
- Rinse thoroughly to remove all soap residue.
- Allow the cover to air dry completely before placing it back on the scale.
- Do not use abrasive cleaners or scrubbers, as these may damage the silicone material.

Image 11: The silicone cover being rinsed under a tap, demonstrating its washable nature.
6. Troubleshooting
This section addresses common issues that may arise when using the HARIO Coffee Scale Polaris, which the silicone cover is designed to protect.
- Error "EEE" Appears: This indicates that the total measured weight exceeds the maximum display capacity of "999". Ensure the weight is within the scale's operational limits. Also, ensure the scale is used in a stable environment, away from drafts or wind, which can affect readings.
- Cannot Turn Off Power: Avoid operating the scale with your hand directly on the weighing platform. Ensure the scale is placed on a horizontal, stable surface during operation.
- Auto-Timer Does Not Activate: Refer to the main Polaris scale manual for specific instructions on activating and troubleshooting the auto-timer function.
- Percentage Display Does Not Appear: Refer to the main Polaris scale manual for specific instructions on display modes and settings.
- Polaris Mode Does Not Activate: Refer to the main Polaris scale manual for specific instructions on activating and using Polaris mode.
Important Usage Notes for the Scale:

Image 12: Avoid using the scale in areas with strong air currents, such as near air conditioners, as this can affect measurement accuracy.

Image 13: Do not press or operate the scale with your hand directly on the weighing platform, as this can lead to inaccurate readings or operational issues.
7. Specifications
| Feature | Detail |
|---|---|
| Model Number | C-CST-B |
| Brand | HARIO |
| Color | Black |
| Material | Silicone Rubber |
| Product Dimensions (W x D x H) | 13.0 x 1.5 x 11.9 cm (approximate) |
| Product Weight | 93 g |
| Package Dimensions | 14.7 x 13.9 x 2.5 cm |
| Batteries Required | No |
| Country of Origin | China |
8. Warranty and Support
For warranty information and customer support regarding the HARIO Coffee Scale Polaris Silicone Cover, please refer to the official HARIO website or contact HARIO customer service directly. Specific warranty terms may vary by region.
Official HARIO Website: https://www.hario.jp/





