That's Memphis Postcard 5x7 Rectangle Horizontal

Postcards are one of the most affordable and highly effective direct-mail marketing strategies. Postcards work for every industry, business to business and business to consumer. A postcard is a quick and easy way to share important information. They're popular because they're simple to create and inexpensive to print, and unlike other forms of direct marketing mail, postcards almost always get read. When it comes to postcards, nothing is faster and more cost effective than online printing.