Kamennyi TsvetokSix intersecting circles (in steps of 120°) in a 2D-puzzle of soviet origin.
Kvadratura KrugaA puzzle from the soviet era. Its title translates to "Squaring the circle"
LooperThree circles on one line, each allowing 180° turns with a shallow intersections.
LoticaThe original Lotica without images on the pieces.
Mad TriadTen overlapping wheels. Each with six segments.
Magic DigitFour intersecting circles with just seven pieces visible out of twelve pieces in total, with an additional flipping mechanism for the pieces.
Magical GearsA puzzle with two intersecting circles. Produced in low quantity in four different variants.