China Zhejiang Sanmen Herod Mattress Co.,Ltd. locates at the southeast of China, it is only one and half hour's drive from Ningbo airport and Hangzhou airport, very convenience at the transport and shipment. We specialized in making various of springs, extension spring, torsion spring for above 8 years, our main products, extension springs, torsion springs is bonnell spring, serpentine spring for mattress and sofa usages, compression spring, extension spring, torsional spring, leaf spring, extension spring, torsion spring and other kinds of springs for automobile, machine, artcraft and other usages. Because of skilled workers, advanced equipments, strict management, our products, extension springs, torsion springs, garage door extension spring, garage door torsion spring, garage torsion spring, torsion bar spring, double torsion spring, spiral torsion spring, garage extension spring, helical torsion spring, small torsion spring, overhead door torsion spring, rubber torsion spring, adjusting torsion spring, garage doors torsion spring, heavy duty torsion spring, flat torsion spring, large torsion spring, overhead garage door extension spring, stainless steel extension spring are of high quality and they are warmly welcomed by our customers from domestic and abroad of China.