SureSTART™ Level 1 WebSeal™ Square 384-Well Plate Sealing Mats are designed for everyday chromatography analysis. They provide an affordable choice for use with most HPLC/UHPLC instrument types and are ideal for non-regulated laboratories using water and polar solvents. These 384-well plate sealing mats are specification certified to ensure autosampler compatible physical dimensions and conform to ANSI-SLAS 4-2004 standards.