Coway CEO Seo Jang-won (right) and Korea Productivity Center Chairman Park Sung-joong pose for a photo at the 2026 National Customer Satisfaction Index awards ceremony held at Lotte Hotel Seoul on Tuesday. (Coway) Coway said Thursday it ranked first in four categories of the 2026 National Customer Satisfaction Index.The annual index, compiled by the Korea Productivity Center, measures customer satisfaction based on surveys of actual product and service users.Coway topped the rankings in water purifiers, mattresses, healthcare massage appliances and rental care services.The company retained its No. 1 position in the water purifier category for a third consecutive year, led by its Icon Ice Water Purifier series. The lineup was recognized for its rapid ice-making technology, compact design and range of color options.In the mattress category, Coway's premium sleep and wellness brand Berex was recognized for products including the M-Series Massage Mattress Bed and the R-Series Stretching Motion Bed, which combine sleep functions with massage and stretching features.Its Pebble Chair 2 ranked first in the healthcare massage appliance category, earning recognition for its massage performance, compact size and furniture-inspired design.Coway also topped the rental care services category with its Cody Care Service, which provides two scheduled maintenance visits during the rental period and real-time mobile notifications on service technician arrivals."Leading four categories reflects the trust consumers place in Coway's products and services," said Seo Jang-won, CEO of Coway."We will continue to deliver innovative products and services that improve customers' everyday lives."