Advantage II - Small Dog (under 4.5kg)Advantage II - Medium Dog (4.6-11kg)Advantage II - Large Dog (11-25kg)Advantage II - Extra Large (Over 25kg) Advantix - Small Dog (under 4.5kg)Advantix - Medium Dog (4.6-11kg)Advantix - Large Dog (11-25kg)Advantix - Extra Large (Over 25kg) Advantage Multi 9Advantage Multi 18Advantage Multi 10, 20, 55, 100 Advantage II K9 Advantix Advantage Multi