Lee Filters Zircon LED Lighting Pack are used for colour correcting LED lights. The standard gel filters sold by LEE also correct LED lights but over time the intensity of LED fades the standard gel, forcing them to be replaced after 30 hours of use. The new Zircon filters have been developed in a way that ensures they last longer when used with LED lights. Retain at least 80% effectiveness over that time. Stocked in a pack of 12 x 12″ pre-cut sheets that can be cut to size.