 Carry Optics was introduced by USPSA in July 2015, and competitors could participate in the division from mid September 2015.Initially the maximum weight limit was 35 ounces (approximately 992 grams) including an empty magazine, but in 2016 the maximum weight limit was raised to 45 ounces (approximately 1275 grams) including an empty magazine, so that most Production legal pistols can be used once a red dot sight is attached.Initially there was a 10-round magazine capacity limit, but from 1st February 2017 the magazine capacity limit was raised to any magazine that can fit a 140 mm USPSA gauge (measuring 141.25 mm)

The USPSA Single Stack Division (short "SS") caters to the traditional 1911 fan, and its IPSC equivalent is the Classic division.