Each dog has a personality of his own and hence may react rather differently to training. Luna and Astro are the epitome of such phenomena. They both employed Halo Collar 5 and used the identical boundary cue set during the learning period. Yet they had quite different reactions to training. Luna was happy with keeping her distance; Astro was naturally interested and ready to explore everything around. Their differing personalities had a big impact on how they approached Halo