The S&G 9A2 is essentially the same but the pistol grip was replaced by a more practical polymer spade grip.
The S&G AN9A1 is an aircraft variant. It has an eltrically assisted feed to help up the rate of fire to 1200 rpm it also has an air cooled barrel and flash hider.
The S&G 9 is a .50 caliber heavy machine gun. It has a selcectable rate of fire of 600 rpm, 800 rpm, and 950 rpm. It can be mounted on a tripod, aircraft, vessels and land vehicles. It was made to replace the aging M2 within the British and Canadian militaries but was soon accepted by many other Commonwealth militaries such as Australia and New Zealand.