... spring,seat spring,no sag spring,belong to sofa part. metal spring clip (Sofa parts), zigzag spring,no sag spring,sinuous ... ,back spring belong to sofa part or sofa fittingspringFeactures:(1) metal spring clip No.4870 (used with Zigzag springs) 1).significantly ... clip 5).soundless under strain 6).Stapling on wood and metal frames 7).no marking, only put on the frame and fix ...