we can manufacture sofa vericle springs as your requriements ,also 12 types as below are avalable :2.3*110*4,3*130*65,3.5*130*6,

4*175*6,4*180*6,4*150*54*130*5,4*170*6,

4*160*5,3*160*7,3.5*177.8*5,3.5*160*7