COSRX Master Patch X-Large are niacinamide-enriched patches in an oversized, contoured shape that can treat multiple imperfections at once. Each patch works overnight to clear problem areas of whiteheads, blackheads, pustules, and papules by breaking down bacteria while simultaneously hydrating the skin’s surface to speed up healing. The hydrocolloid patches are ultrathin and measure 30 x 60 mm, making them comfortable to wear and suitable for use both day and night.