#21 experimental AP-Grenade (Hollow Charge) for 20mm AA-Gun 30 & 38, used with 66mm Rifle-Grenade-Launcher (a bigger Copy of K98 Rifle-Grenade-Launcher), complete made of Steel, inert filled, Copper Driving-Belt
#98 Launching Cartridge for 20mm Rifle-Grenades
This one is not for the 2cm launcher cup but for the 66mm cartridge which had an own case and was fired by a separate weapon design.