The M101A1 is a light, towed cannon that fires a 105mm (4.2-inch diameter) projectile. It is deployed in the field when the use of the 155mm howitzer is not practical.

The M101A1 105mm Light Howitzer can be used for direct (line of sight) or indirect fire. The cannon consists of a tube assembly, breech ring and locking ring, and is mounted on the recoil sleigh assembly. The firing mechanism is activated by pulling a lanyard.

The cannon is single-loaded and air-cooled, and it uses semi-fixed ammunition, which can be adjusted for distance and target. The carriage has a single axle and split trail. The trails are divided when the weapon is positioned and set up, drawn together and locked during travel. The recoil mechanism is a constant hydro-pneumatic type shock absorber, installed in the cradle of the carriage.

A maximum rate of fire of 10 rounds per minute can be reached. A sustained rate of 3 rounds per minute is possible with a capable crew.