Made in Australia, this early space gun used a brass plunger system to fire a cork. (The metal mechanism makes the Pow'r Pop much heavier than it looks.) Like many such toys, it included a whistle built into the base of the handle. Not a particularly complicated toy, I know, but it's definitely one of the nicest looking ones. The Pow'r Pop has always been high on my want-list, but it's an extremely rare toy; I finally landed one after nearly five years of searching.
The Pow'r Pop was available in three different color variations: This yellow one, a red one with blue grips and yellow tip, and a black one with turquoise grips and tip. The black is the most difficult to find.
I don't really know much else about the toy. I've heard a 1951 date bandied around, but I've never seen proof. Thanks to Steve Baker for confirming this!