Do Not Erase Magnets for whiteboards from OptiMA® Super colorful magnetic do not erase warning signs to protect sensitive information written on your whiteboard. OptiMA's collection of super strong American Made magnets are available in three different sets. The full set includes 8 strips at 32" long x roughly 2.2" wide and 8 squares in 3 sizes of 3" x 3", 4.75" x 4.75" and a larger 6.25" x 6.25". You can also order just a set of 42" long strips, 4 yellow and 4 red or the square set which has all 8 of the red and yellow squares only. Save all of your important information written on any magnetic dry erase board or chalkboard for use later in the day or even the next day. Let other teachers, colleagues or custodians know what can and can't be erased with our Please Do Not Erase magnets. Proudly made in the U.S.A.