Vintage briefcase anti-theft device - GIF

[Frank S]

I wonder if it might be compressed gas operation?

It could be although if it were the gas cylinder would have to be very cmall in diameter and it wold be a 1 time activation.
The more I think of it I may have touched on the means with the tape measure comment. instead of 40 or so individual slightly tapered segments it could have been a single or perhaps 2 coiled springs Which actually makes more seance because a coil would have stored energy. 2 coils would extend in each direction allowing for the major diameter to be in the center and tapering to the ends this would lend to the staff being balanced better for twirling.

[JTG]

The collapsible staff functions the same way as a paper yo-yo, only made from a strip of metal and biased towards remaining extended.

If anyone would like to investigate further, they go for $5-7 on ebay.

[Jon]

7 bucks, not bad! Let me know if you see a cheap one that doesn't take a month or two to ship from China; it looks like it's good for probably at least 45 minutes of entertainment before my son breaks it.