http://en.wikipedia.org/wiki/Glock said:The Glock 24 is a .40 S&W competition variant of the full-size Glock 22 similar in concept to the target Glock 17L model. Additionally, a compensated ported-barrel version designated the 24C was also produced. The Glock 24 was introduced in 1994 and officially dropped from the company's regular product lineup upon the release of the Glock 34 and 35.[54] However, Glock continues to make small batch runs of the Glock 24 and 24C (as well as the similarly sized Glock 17L) at irregular intervals to satisfy consumer demand built-up for factory-new units, as shown by the release into the marketplace of new production of these models during the spring of 2010 and summer of 2011