Its outstanding protective capability is leading to high reliability. By combining much greater hardness than chemically strengthened glass and greater flexibility than sapphire crystal glass.
Clear glass ceramic is the ideal material for protective filters that achieve over 10 times the strength of a conventional protective filter.
World's first Clear Glass Ceramic Protective lens filter

Sigma 95mm WR UV Filter
Features:
- Helps to Absorb Ultraviolet Light
- Reduces Bluish Cast of Daylight
- General Protective Filter
- Water, Oil, and Static Repellent
Specifications:
- Filter Type: UV
- Filter Factor: 1 (0 Stop)
- Shape: Circle
- Circular Size: 95 mm
- Front Accessory Thread / Bayonet: 95 mm
- Warranty: 36 Months
This Sigma WR UV filter is also useful as a general protective filter to leave on a lens at all times. This filter helps to reduce dust and moisture from reaching your front lens element and provides additional protection in case of drops or situations where scratching could occur. This Sigma WR UV Filter is coated to repel water drops and resist smudging from fingerprints. It is also treated to exhibit antistatic properties to prevent microscopic dust from clinging to the front surface. This helps to ensure sharp images. The Sigma 95mm WR UV Filter is a general use, clear filter that helps to absorb ultraviolet light and reduce the bluish cast of daylight. This filter is especially useful when photographing at high altitudes or around bodies of water. No additional coloration or contrast is provided, allowing you to pair this filter with others.

Able to absorb ultraviolet light and prevent bluish tones from ruining photos captured in sunny shooting conditions, the Sigma 67mm WR UV Filter will not add any additional colouration or contrast. This is why it can easily be paired with other filters.

The oil and water repellent property of the Sigma 67mm WR UV Filter ensure water droplets and fingerprints are repelled with ease. Clarity and sharpness is further boosted by its antistatic nature which repels microscopic dust particles. As the filter prevents dust, dirt and scratches from reaching the front lens element, this UV filter doubles as a general protection filter.