Since June 1st 2012 all manually controlled FEZER lifters are equipped with the unique "main switch supervision". An alarm goes off if loads are engaged only by the remaining vacuum without the lifter being operational. This situation occurs more often than imagined as most operators switch off the lifter after the operation to keep the noise level at the work station low. In hectic times it is easily forgotten to reactivate the lifter. Despite this the visual supervision gauge may show in such cases "code green". In those cases the new safety concept takes effect. When loads are engaged while the main switch is off an additional vacuum switch recognizes this and activates the built-in howler. An unmistakable alarm goes off and warns about the danger and thus helps to prevent accidents and tremendously increases the work safety.