Dual Circle - surprisingly enough is two interlocking circles - pieces move when the circles are turned.

• Inventor: Oskar van Deventer
• Mechanism: Unique
• Patents: Unknown
• Producer: Hanayama
• Year: Unknown
• Original Price: $14.50 USD
• Current Price: $71 USD

Two interlocking circles one red and black the other blue and black. When one circle is rotated it twists the other circle and changes the colour. The goal is to return both circles to their full colours. The idea was conceived by Bram Cohen. The puzzle was designed by Oskar van Deventer.

Price Tracking Data

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	Sale Date	Price (USD)	Sale Type	Condition	Package Condition	Notes	Contributors	Edit
	Oct 22 2012	$71.00	eBay Auction	Mint	Mint	None	Oli Sovary-Soos
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