Roinik;c-158959 wroteYou can always test them with a 1.5V dc power supply. I'd expect them to be directional as they are an electro-magnet designed to lift the pin against a spring. Hence the coil will obey the right hand rule.
Most people reasonably assume this but, like a solenoid, driving current through the winding causes the plunger to move toward the magnetic field, i.e., into the region enclosed by the winding. Reversing the polarity of the applied voltage does not reverse the direction of movement, because a typical plunger is just a piece of metal (not a magnet), and thus it is always attracted to (not repelled from) the magnetic field.
If there's no positive or negarive markings it doesnt matter.
Try Ians suggestion test leads with a 9v battery and you will find it fires normally either way you connect the polarity