Ideal for recapping most 12, 13 and 16 millimeter evacuated glass blood collection tubes Designed for easy-on and easy-off use, featuring double thumb tabs Flexible closures protect from aerosols of highly infectious microorganisms. Guard samples against cross-contamination and laboratory work areas against infection and spillage Precision-molded, low-density polyethylene (LDPE) designed to fit firmly on the tube Closures remain sturdy under most rigorous laboratory procedures, including centrifugation. Color-coded for easy sample identification Not suitable for autoclaving There are 1,000 red snap cap tube closures in a bag. .