Notch:A12 Non-Skirted Standard Profile: Tube height 21 mm Clear Tubes Thin walled tube for best heat transfer Made of USP VI Polypropylene Free of DNase, RNase, DNA, PCR Inhibitor, ATP, Endotoxin. All products are ready to use in PCR Tearable design to accommodate variable numbers of samples (multiple of 8) and minimize waste When torn into 8-strip format, all the 8-strip caps of Gunster can be used for closure. Small package can avoid contamination by different researchers