Check out which companies are making headlines after the bell Monday:

Yahoo - The Internet company named former Google executive Marissa Mayer as its new president and CEO . Shares rallied in extended-hours trading. (Click here for after-hours quote.)

Cintas - The uniform maker posted earnings of 60 cents a share, in line with expectations, but reported sales of $1.05 billion, below expectations for $1.07 billion. In addition, the company handed in a 2013 full-year guidance that was at the lower-end of the expected range, pushing shares lower in extended-hours trading. (Click here for after-hours quote.)

FlirSystems - The thermal imaging systems manufacturer posted preliminary earnings of 30 cents a share, excluding one-time items, on revenue of $338 million, disappointing analysts who had expected earnings of 36 cents a share on sales of $380 million. In addition, the company handed in a weaker-than-expected full-year outlook, citing weakness in Europe. Shares fell in extended-hours trading. Flir will release its full results on July 26. (Click here for after-hours quote.)