That means the component can work with voltage 12V, if the 12V is constantly applied to the component or can work with 24V, if the voltage 24V is applied to the component in astable regime with duty cycle 25% (ti/(ti+tp)=0,25). Or with words, one can apply to the component, for example 24V for time: 1 second and 3second there has not voltage to the component and again: 24 V for time: 1 second and 3second there has not voltage to the component etc.
yea dragan is right...if i were u id just hook it up to a 12v battery like a car battery or some sort and just go from there...thats the easiest way to my knowledge...