The following are the common specifications of the single spring used for the spring unit. Wire Diam.: 1.6-2.4mm Top Diam.: 4.5-5.5cm Waist Diam.: 6.5-7.5cm Border Wire: 4.8-5.0cm Height: 8-23 Turns: 4-7 We have two kinds of packing ways. Roll packing---without the border wire Flat compress packing---with the border For the bonnell spring, 4 turns, height range 85mm - 105mm 5turns, height range 135mm - 150mm 6turns, height range 145mm - 170mm Steel wire range, 2.1mm -2.4mm Helical wire range, 1.3mm or 1.4mm Border wire range, 4.0mm -5.0mm What's more, we can make other special size according to your detailed requirements.Our company specialize in producing roll mattress, foam mattress. Compress spring mattress, leather bed, and sofa set. 1. Let body shape and mattess contact perfectly, It is good for protecting the skeletal. 2. Automatic balance and regulate pressure, promote the blood circulation. 3. When human impact on the mattress, it will automatically generated, saving energy consumption springback booster, prolong the period of human impact. 4. To prevent human waist and knees in the up and down movement, avoid friction trauma sciatic neurosis. 5. To promote human body in the application of physical and emotional function, achieve the highest realm. 6. Reduce the bodys resistance by 50% for easily. 7. Make sure the mattresss internal air circulation, maintain clean and sanitation. 8. Eliminate the body's metabolism and peculiar smell. 9. Luxurious imported brocade, fabric wear comfortable. 10. For the special recommentation of the international sleeping center, its the best for the 35-50 people using.