The ISM Connect 300 was a Monster Energy NASCAR Cup Series stock car race that was 317.4 miles (510.8 km), traditionally held in mid-September at the New Hampshire Motor Speedway in Loudon, New Hampshire, the other one being the Ambetter 301 in July.

New Hampshire Motor Speedway is a 1.058 mi (1.703 km) oval speedway located in Loudon, New Hampshire, which has hosted NASCAR racing annually since 1990, as well as the longest-running motorcycle race in North America, the Loudon Classic. Nicknamed "The Magic Mile", the speedway is often converted into a 1.600 mi (2.575 km) road course, which includes much of the oval.