A thin film transistor array including a substrate, a plurality of scan lines, a plurality of data lines, a plurality of thin film transistors, an etch barrier layer and a plurality of pixel electrodes is provided. The dial positioned beneath the disc provides a marking in the form of a marker circle with radial markers numbered 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. The central section of the vascular graft may be constructed differently from surrounding self-sealing regions, in order to provide kink resistance following the clamping of the graft.