It's really just the cheapest plastic tournament set they sell.
Some other genius came up with taking these sets and punching a hole in them.
They sell as keychains on ebay !!!
Whole set $6 ... I piece with a piece of rope/chain $2.
Genius !!!
Someone always comes up with creative ways to stick it to the chess player.
When I first started playing, there was a chess set that moved its on pieces. It started out around $600 and slowly whittled down to $150.
It was a great idea but way too expensive.
The higher levels on those old chess set/computers would take 30 minutes to an hour per move (although I never actually owned that one).