Vacuette® Venous Blood Collection Tube, 13 x 75 mm, 3 mL, Light Blue Cap, 1 Case of 1200 Whirpool Chairs Tables 44 60 * Conforms and Instrument and Solution Stands 44 60 * Conforms and supports the lower back promoting muscle relaxation and proper alignment of the back * Built in ventilated lumbar pad provides additional support to the lumbar area * Breathable nylon mesh wrap with adjustable hook and loop front closure holds the belt in place * Lightweight Standard 250 Lb Mixing ratio is one part citrate to nine parts blood when tube is filled appropriately as indicated by fill mark on label 18 month shelf life from date of manufacture