Polyethyleneterephthalate (PET), and to a lesser extent Teflon have become the major synthetic grafting material. Unlike nylon, Ivalon, and Vinyon-N which lose their tensile strength after implantation, PET and Teflon remain essentially unchanged even after long periods. TRICOMED S.A. produces the family of the knitted vascular implants Dallon made from PET fibres including: Dallon, Dallon H, Tricogel. Both Dallon and Dallon H are manufactured in a form of double (external and internal) velour surface using multifilament yarn and having optimal graft design (a variety of sizes and lengths). The velour surface gives the surface a velvety, plush texture, which improves tissue in--growth. Moreover, Dallon H is a unique vascular prostheses showing the increase in the blood susceptibility that is useful for 4 times less blood demand during preclotting as compared with standard prosthesis. Tricogel graft is made of thin-wall prostheses sealed with the porcine gelatin that provides intraoperative tightness (without preclotting) and the optimal healing process. Hydrophilic behavior of the graft is observed as an instant moistening of the surface with patient's blood and as sweating. The blood stream does not dissolve nor washes away the gelatin but causes the gelatin film to swell, which makes a better tightness. The work will describe the properties of manmade vascular grafts as well as their applications in the vascular surgery.