The Rain OK EZ Quick Side Mirror Super-Hydrophobic Film, released by Bullsone's Rain OK brand. [Provided by Bullsone]
The Rain OK EZ Quick Side Mirror Super-Hydrophobic Film, released by Bullsone's Rain OK brand. [Provided by Bullsone]

Automotive products company Bullsone has launched a new film designed to help drivers maintain clear side-mirror visibility in rainy conditions. The product targets growing demand for lateral visibility management as intense, short-duration rainfall from localized downpours and typhoons becomes more frequent.

Rain OK, Bullsone's glass care brand, announced Wednesday the release of the Rain OK EZ Quick Side Mirror Super-Hydrophobic Film.

The film adheres directly to the side-mirror surface and causes water droplets to bead up and roll off quickly rather than lingering, helping drivers maintain a clear view when changing lanes or parking in the rain.

Driving conditions in wet weather have grown increasingly challenging. The Korea Meteorological Administration's "113-Year Climate Change Analysis Report," covering data from 1912 to 2024, found that while the number of rainy days has declined, total precipitation has increased — meaning rainfall intensity has risen and heavy concentrated downpours have become more frequent. In short, when it does rain, it tends to rain harder.

The film uses a nano-imprinting process that creates microscopic patterns on its surface at the nanometer scale. Water beads into droplets rather than spreading or pooling, then rolls off quickly.

Bullsone said that unlike some products that use a hydrophilic approach — spreading water thinly across the surface — this film takes a super-hydrophobic approach that actively repels droplets. The focus is on rapidly clearing water from the side mirror even in heavy rain to keep the driver's view sharp.

Based on its own research, Bullsone said Rain OK is the only brand in South Korea to have released a general-purpose, side-mirror adhesive film using nano-imprinting-based super-hydrophobic technology.

The product comes in a two-piece set for both the left and right side mirrors. Drivers can apply it themselves, and it retains its water-repellent performance even after car washes. Bullsone also highlighted that the film resists deformation when the mirror's heating element is in use and leaves no residue when removed.

During the monsoon season, maintaining clear lateral visibility is just as important as forward visibility. When water droplets form on side mirrors, checking blind spots while changing lanes, navigating narrow streets or parking can become difficult. That is why Bullsone is positioning the product as a lateral visibility management tool.

"As localized heavy rain becomes more frequent, managing lateral visibility while driving in wet conditions is increasingly important," a Bullsone official said. "Starting with the Rain OK EZ Quick Side Mirror Super-Hydrophobic Film, which anyone can easily apply, we will continue to introduce glass care technologies and products that help drivers stay safe on the road."

Meanwhile, Bullsone posted sales of 46.4 billion won ($30.4 million) and operating profit of 5.8 billion won in the first quarter, up more than 10 percent year-on-year for both metrics — the company's best first-quarter earnings on record.


kwater@heraldcorp.com