---
description: Generic sapphire crystal for Frederique Constant Slim Line 306S4S6B3. 35mm domed, blue AR. Aftermarket replacement.
title: Sapphire Crystal for Frederique Constant Slim Line
image: https://www.soflypart.com/wp-content/uploads/2024/01/DSC09661.jpg
---
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- **Generic Frederique Constant Slim Line 306S4S6B3 Sapphire Crystal 35mm**
[](https://www.soflypart.com/wp-content/uploads/2024/01/DSC09661.jpg)
# Generic Frederique Constant Slim Line 306S4S6B3 Sapphire Crystal 35mm
$50.00
You Saved
| Brand | Choose an option Frederique Constant- 
Clear |
| --- | --- |
### Discount
| Quantity | Discount (%) | Price |
| --- | --- | --- |
| 1 - 2 | — | $50.00 |
| 3 - 4 | 5% | $47.50 |
| 5 - 9 | 7% | $46.50 |
| 10 - 14 | 10% | $45.00 |
| 15+ | 15% | $42.50 |
### Discount
| Quantity | Discount (%) | Price |
| --- | --- | --- |
| 1 - 2 | — | $50.00 |
| 3 - 4 | 5% | $47.50 |
| 5 - 9 | 7% | $46.50 |
| 10 - 14 | 10% | $45.00 |
| 15+ | 15% | $42.50 |
Generic Frederique Constant Slim Line 306S4S6B3 Sapphire Crystal 35mm quantity
Add to cart
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[Checkout](https://www.soflypart.com/checkout/)
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## Product Description
This is a high‑quality generic replacement sapphire crystal for the Frederique Constant Slim Line reference 306S4S6B3, measuring 35.0mm (diameter) × 2.5mm (overall height) × 1.0mm (edge thickness) with a domed profile and a blue anti‑reflective (AR) coating. Made of synthetic sapphire glass (Mohs hardness 9), it offers exceptional scratch resistance and excellent optical clarity, serving as a direct substitute for a damaged or scratched original crystal.
## Features & Function
- **Sapphire Crystal** – Mohs 9, extremely scratch-resistant and optically clear.
- **Domed Profile** – Classic curved shape, enhances the watch’s elegance.
- **Blue Anti-Reflective Coating** – Reduces glare, improves dial visibility with a subtle blue tint.
- **Precise Dimensions** – 35.0mm diameter, 2.5mm total height, 1.0mm edge thickness, fits original case groove.
- **Generic Aftermarket** – Non-original but dimensionally accurate for 306S4S6B3; cost-effective.
| Parameter | Details |
| --- | --- |
| Compatible Model | Frederique Constant Slim Line 306S4S6B3 |
| Type | Generic (aftermarket, not genuine) |
| Material | Synthetic sapphire crystal |
| Shape | Domed |
| Diameter | 35.0 mm |
| Overall Height | 2.5 mm |
| Edge Thickness | 1.0 mm |
| Coating | Blue anti-reflective |
## FAQ
**Q1: What is the difference between blue AR coating and clear AR coating?**
A: Blue AR coating reduces glare while reflecting a subtle blue hue – a signature feature of many Frederique Constant Slim Line original crystals. Clear AR coating only reduces glare without the blue tint.
**Q2: How to tell if the crystal has blue AR coating?**
A: Tilt the crystal under a light. A vivid blue reflection indicates blue AR coating; white or pale yellow reflection means no blue coating. This product features blue AR coating.
**Q3: Will the watch retain its original 30m water resistance after replacement?**
A: Due to tolerances in generic parts, the original 30m rating cannot be guaranteed. Always perform a pressure test after installation. Treat as splash‑proof only.
**Q4: Is a gasket included with this crystal?**
A: No. Purchase a matching round gasket separately, and apply a thin layer of silicone grease before installation.
## Why Choose SOFLY Watch Parts?
- Fast worldwide shipping within 3 business days.
- Competitive pricing on Seiko/Hattori calibers.
- 3,000+ watch movements and parts in stock.
- Trusted by watchmakers worldwide.
- Personalized sourcing support via **info@soflypart.com** or WhatsApp **+86 18620212114**.
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Made of synthetic sapphire glass (Mohs hardness 9), it offers exceptional scratch resistance and excellent optical clarity, serving as a direct substitute for a damaged or scratched original crystal. Features & Function Sapphire Crystal\u00a0\u2013 Mohs 9, extremely scratch-resistant and optically clear. Domed Profile\u00a0\u2013 Classic curved shape, enhances the watch\u2019s elegance. Blue Anti-Reflective Coating\u00a0\u2013 Reduces glare, improves dial visibility with a subtle blue tint. Precise Dimensions\u00a0\u2013 35.0mm diameter, 2.5mm total height, 1.0mm edge thickness, fits original case groove. Generic Aftermarket\u00a0\u2013 Non-original but dimensionally accurate for 306S4S6B3; cost-effective. 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