I shipped a pair of the time-delay relay modules to Jem back in October of 2008 when I sent out the custom dichros.
Also, the units you linked to won't work by themselves, as they are "on" until you push the button, then they are off for up to 180 seconds before turning on again.
In contrast, the units that Stuka found will be off until you trigger them, and then after an adjustable delay, they come on and stay on until you shut them off.
Adam