Black A-Frame Chalkboard Sidewalk Sign for Wet Erase and Traditional Stick Chalk, 21" x 34" Boards Slide Out for Easy Updating Folds flat for easy transportation and storage. Suitable for outdoor use during fair weather only. Double-sided enables advertising from multiple directions. Use with traditional stick chalk, liquid chalk and wet-erase neon pens. Two, slide-in 21 x 34-inch boards allows you to design messages prior to them being displayed. Displays2go SKU#: AF2134RBKES