Inner spring (Bonnell Spring) we produce: Material: high carbon steel wire1.3-5.0mm Height: 15-20cm, others available as per negotiated Turns: 4/5/6 turns The most popular products we produce: No. Type Size/Inch Height/ In 1 TWIN 36.5" x 73" 7 2 TWIN XL 36.5" x 78" 7 3 FULL 51.5" x 73" 7 4 FULL XL 51.5" x 78" 7 5 QUEEN 58.5" x 78" 7 6 E. KING 74.5" x 78" 7 7 CA. KING 70.5" x 82" 7 Application: making sprig mattress Packing: covered with wooden pallet on top and bottom, then compressed with steel strips, which is excellent for export usage. We are a dynamic bonnell spring producer for the high quality material and sophisticated producing technology. Should you need any more information about of our products, please do not hesitate to contact us.