18"" Designed for specialized floor cleaning and finish applications. Traditionally colored, blue and white, and optimally shaped for smooth, even application of floor finish. Dense 3 - 5 micrometer quality fiber removes more dust, dirt and microbes than conventional cleaning products. Foam liner controls liquid content and release. Advanced hook-and-loop backing... holds-up under harsh laundering conditions and attaches pads more securely. Durable pad construction... third party tested tough... withstands more than 300 launderings. Double finished edges retain mop shape with use over time.