How many levels are there for AVA, and what is included with each level? AVA has four licence levels to suit your application and budget. As the level number increases, additional types of equipment can be controlled. You can upgrade to a higher level if your needs change. AVA Level 1 can control stirring hotplates. AVA Level 2 can control stirring hotplates and overhead stirrers. AVA Level 3 can control stirring hotplates, overhead stirrers and circulators (thermoregulators). AVA Level 4 can control all the equipment from level 3, plus devices such as pumps, balances, pH meters, and vacuum controllers.