Quartet - QRTECKA408 Simple and recognizable, natural cork bulletin boards offer a practical surface for posting notices and course materials in the classroom. Natural cork's excellent pin holding power and resealing properties make for a quality long-lasting surface. The satin finished, anodized aluminum frame is heavy-gauge with crimp construction, a 3/4" frame face width, and all four corners precision mitered for extra strength. Boards sized 3' x 4' and smaller feature Quartet's patented SureLox hanging system, while larger sized boards feature a heavy-duty L clip installation kit for safe, simple, and precise mounting every time.