The Detex ML-1500 Series, Grade 1 Magnetic Lock meets or exceeds 1500 lbs. of holding force to the separation point.  This is powerful enough to hold many doors against a force that will deform or destroy the door before the ML-1500 can be forced open.  Positive, instantaneous failsafe operation is guaranteed, with no moving parts to bind or wear, the ML-1500 Series will release immediately when de-energized by Fire Life Safety System or remote controls.