Aboistop Anti-Bark Collar spray refills are refills for the original kit. Each type of spray collar can use either the Pavlov or the Dynavet refills. The units come with the Odourless spray as standard which is what our behaviour experts recommend, but if the odourless spray does not have the desired effect on your dog, we would recommend that you upgrade to the Citronella and then to the Mustard if required.