1. Cobalt-based 2. Magnetic strip 3. Size:10x51mm Double-sided 5" security strip for books and periodicals Extra-long liner for quicker and easier application between pages Strips fit deeply into gutter, virtually impossible to find and remove Can be turned "off" and "on" again repeatedly, retaining original effectiveness Strips never lose their effectiveness after repeated desensitizing and resensitizing Cannot be shielded by briefcases, backpacks, the human body or other common objects Archival quality adhesive will not affect library materials Compatible with 3M or other electromagnetic security systems

3M Tattle Tape