Easy-Fit Peristaltic pump tubing, standard for Internal Standard uptake, recommended for aqueous acid matrix, 1 pack of 12 pcs. Clear PVC, 2-stop, blue/orange tabs, 0.25 mm id. Standard for ISTD uptake on Agilent 7700, 7800, 7850, 7900, 8800, 8900 ICP-MS.