In order to meet the needs of our customers, the POLAR PLUS stairs have been equipped with the ZeroGravity handrail system - making it much easier to enter the loft, a solid two-point metal lock, and a triple seal in order to improve the comfort and safety of our customers. Of course, there are also the best features of POLAR products such as an 86 mm thick insulated hatch, a low heat transfer coefficient of 0.36W/m2*K and solid workmanship confirmed by a 5-year guarantee. Ud - hatch centre coefficient.