The S4000 collection is a floor springs line with force 1, 2 and 3. Floor spring S 4000 with force1 is particularly adequate in the case of installation on asymmetrical doors, where the narrowest door needs a floor spring with light strength to facilitate its opening. The operation of the compact S 4000 is always guaranteed, also under extreme climatic conditions (-25°C +60°C) over the limits foreseen by the most severe legislations, thanks to the use of a particular thermostatic oil that makes the interventions of regulation occasional. Every floor spring is equipped inside with an overload valve that enters in action in case of abrupt closings. The standard production has the Italian fixed pivot; on request it can be furnished with square to measure and/or with interchangeable pivot.