This special tailor soft firmness system supports your body gently, not adding excessive pressure. Non-metal connection between coils, eliminating commonly heard noise from compatible systems & Brands. Each row of Coils is joined by 2 continuous bonded by thermoplastic adhesive at different level. This prolongs the system usability and maintains its dimension. Each coil works individually and accordingly to different body contour without creating disturbance to your partner. The carbonated steel barrel-size coil is heat-treated for rust-proofing and pre-compression to provide more resilience