Double acting solenoid
This solenoid is a so-called double acting magnet. This means that it can work both as a pull magnet and a pressure magnet.
If the left cable pair (as shown on the drawing below) is connected to 24V, the magnet operates as a pull-magnet (threaded rod is pulled inward),
and if the right cable pair is connected, it works as a pushmagnet (threaded rod is pushed outwards).
ED's is a percentage measure of the connection time.
If the magnet are supposed to work shorter (lower ED), you can increase voltage and get more power.
Lower voltage gives lower force.
Stated holding power applies in ideal conditions without safety factor.