Safety Systems PES: H41q/H51q. Leading the field in safety technology. The first system in the world with the 2oo4D architecture The first 2oo4/QMR system in the world with SIL 3 certification The first system in the world which can be used in single-channel configurations up to SIL 3 Solutions which are optimized in terms of cost by combining freely scaleable availability with constant maximum safety H41q/H51q