Characterised by its exceptionally durable construction, the Sigma WR Ceramic 105mm protection filter is a transparent filter designed to protect the front element from impacts, scratches and other elements. Developed from a transparent glass-ceramic substrate, this filter combines a high transmission value of 99.76% with a hardness superior to chemically strengthened glass and more flexibility than sapphire crystal glass. The result is a shock- and scratch-resistant construction to withstand various impacts during shooting. In addition, a hydrophobic coating has also been applied to resist water droplets and fingerprints, as well as static electricity that attracts dust or other particles. Designed for use in challenging conditions, the unique design of the WR Ceramic protection filter helps to maintain the inherent image quality of the lens while offering a high degree of protection. - Transparent protection filter that protects the front element of the lens from various impacts and scratches without affecting image quality. - Transparent glass-ceramic is a highly durable substrate that possesses a hardness superior to chemically strengthened glass and more flexibility than sapphire crystal glass. - The unique construction features a Vickers hardness of 700 HV, making it resistant to scratches and impacts. This hardness also reduces the likelihood of scratches or chips that could lead to filter breakage. - Rather than simply hardening the surface structure, transparent glass-ceramic involves a heat treatment process that precipitates microcrystals of a mineral called spinel to achieve consistent and uniform resistance across the entire surface of the filter. This resistance also allows the filter to be remarkably thin and lightweight. - A hydrophobic (WR) coating has been applied which, in addition to preventing water and oil from adhering to the filter surface, also helps to minimise ghosting and reflections. This coating reflects 0.24% of light, giving an overall transmission value of 99.76%. - The WR coating also serves as an antistatic coating, which helps to repel dust or other particles that could adhere to the surface of the filter. - The included rigid acrylic case protects the filter when not in use and has been designed to prevent any accidental and unwanted opening.