Add layers to your marketing campaign with a promotional product that works any time of the year! Constructed from 20 mil magnetic material, this 4″ x 4″ square shape calendar magnet is an ideal way to get your name, logo or personalized message in the hands of your clients. Writing on magnets is only possible with permanent markers. They are perfect for promoting any type of industry, project or event. Great for tradeshows! These are for indoor use only, for outdoor magnets see our OSS-series.