ThinkFun Gordian's Knot, Model:6820-T

Think Fun A-ha! Square Fit Brainteasers

a-ha! Rec-Tangle

Think Fun Shape By Shape

Think Fun Square by Square

ThinkFun Adams Cube

Think Fun Fidgitz Twisty Brainteaser Puzzle - Perfect for Silent Fidgeting, Combines a Fidget Toy with a Puzzle

ThinkFun Block By Block

ENIGMA Hanayama Cast Metal Brain Teaser Puzzle (Level 6)

ThinkFun Zig Zag Knot

Think Fun Shape By Shape

Back-Spin Handheld Puzzle Game

Fat Brain Toys Coggy Brainteasers for Ages 6 to 12

MONKEY POD GAMES Domino Cube

Fat Brain Toys Ivan's Hinge Brainteasers for Ages 8 to 12