Thin-Walled Economy NMR Sample Tubes, 5mm, 500 MHz, Part Number: 82005-328. Kimble NMR Sample Tubes, 5 mm, 400 MHz, Part Number: KT897265-0000. Through Aijiren TechSci: Bel-Art SP Scienceware 5 mm OD Thin Walled Precision NMR Tubes, Part Number: 16-800-468. Kimble NMR Sample Tubes, 5 mm, 400 MHz, Part Number: KT897234-0000.