Strong Magnets: Strong enough to hold all kinds of poster, picture, photo and artwork with flat surface. Easy Operation: Just place your poster into the correct position and clamp it, hang it up with a hide rope. Changeable & Resuable: No tape, no damage. You can change up the poster or kids canvas artwork from time to time as you like. Wide Compatibility: Not only a 31cm poster frame, but also can be used for a poster of less or more than 31cm in width. Kindly Note: Big thickness of your poster may affect the magnets, so it might not be for thick poster or canvas.