STRONG MAGNETS: strong enough to hold all kinds of poster, picture, photo, artwork, maps and even thicker paper and types of canvas with a flat surface. CHANGEABLE & REUSABLE: It takes just 15 secs to change the poster or kids canvas artwork from time to time as you like with no tape and no damage. Simply pull apart poster hanger bars, place artwork and replace the front to hold posters in place. WIDE COMPATIBILITY: 22CM magnetic poster hanger made of natural sustainably sourced wood is very suitable for your 21x30 20x16 posters or any other art with a width less than or greater than 22 cm. EASY OPERATION: just place your poster into correct position and hang it up with matching cord string. KINDLY NOTE: the magnetic hanger may not be suitable for thick posters as it will affect the magnet. Posters are not included in this package.