Core with a single frame with the fabric winding, the whole no joints. Curing the annular zone, with the ends of the perimeter size of the standard, no bell, belt drive without deviation. Cover with plastic using high-strength wear-resistant rubber formula, long life, with uniform thickness, surface smooth, smooth operation, accurate measurement. Q326 Track features: 1, high strength, transmission power is big. 2, flex, and do not slip. 3, cross-transmission, connection is easy. 4, the elongation is small, durable