The GLM is a single-shot 40 mm x 46 LV grenade launcher module. In its basic design, it fulfils the function of an under-mounted secondary weapon. The GLM can be combined with all Heckler & Koch assault rifle models via an HK standardised interface. Additional interface adapters make it possible to attach the grenade launcher to third-party weapons. Target acquisition is via a flip-up ladder sight for ranges up to 350 metres.