***Certified PLUS (Cert+) Level 2 Certification. Limited Volume Specialty Snap-Top Vials and Seals / Closures. • Microsampling Low volume insert, 300 µL, 6x29mm with plastic spring 100/pkg. Manufacturer, Waters. category, Micro Inserts. type, Insert. volume / package size, 250 µl. material, Polypropylene (PP). height, 29 mm