Open the lock and lock it again! The design is evocative of a study padlock. Just pick it up and you'll quickly gain an appreciation for the challenge that lies ahead - this puzzle will not open easily! The interior is comprised of two elliptical pieces, locked together tightly around the circular pieces and obstinately refusing to be released. But don't give up! Repeatedly separate and then put them back together and prove you have what it takes to unlock this riddle. The theme is "obstinacy." Designed by Korean designer JinHoo Ahn. Difficulty: 5/6. Package size: 7,5 cm x 11,5 cm x 4,5 cm.