Back in the day blades were expensive and made from carbon steel, stropping them would extend the life of the blade and this was the reason for the creation of this device. Unlike the Valet razors Ever Ready razors does not have a 'built in' stropping action. Today this is mostly a novelty, as i do not know any folks who would give up the comfort of a modern day blade for the vintage version.
Something for the collector, or the guy who quit smoking and needs to keep his hand busy with random tasks while sitting at a desk, its nice to fiddle with!