Harmony Frosted Glass Square Corner Markerboards are eco-friendly - 100% recyclable and made from recycled glass and sand. Unframed boards feature 1" square corners, square standoffs and flat polished edges. Tempered glass,.25" thick, provides a non-porous surface that will not ghost or stain and works with standard dry erase markers. With the rear face frosted for a transclucent appearance, marker visibility is best when mounted on light to medium colored walls. Four or six pre-drilled mounting holes are inset into the glass and 1" diameter round satin aluminum standoff hangers create a 1.25" spacing between the wall and glass. The board features a clear acrylic rear-mounted accessory holder, complete with markers and eraser. Made in the USA.