The weapon consists of an extendable launch tube with an integrated 9 mm (0.35 in) spotting rifle and 1× sight.

The rounds it uses are quite unusual, consisting of a 9 mm tracer bullet loaded in a necked up 7.62mm NATO shell casing, with a .22 Hornet blank mounted in the base of the larger case, providing the propellant charge.

The warhead is a HEAT shaped charge and could penetrate 700 mm (28 in) of rolled homogeneous armour at 90 degrees, as was taught to soldiers trained on the weapon system in the British Army, Royal Navy (Royal Marines) and RAF Regiment[citation needed].

It was also taught that sloped, composite and reactive armour[citation needed], would reduce the penetration and would be an important factor when selecting the aiming point.

Addermine is an acoustic sensor system which uses the LAW 80 as a kill mechanism to create an anti-armour off-route mine.