During the early period of the Sith Empire, the Sith came to realize the advantages of automated soldiers. Thus, they manufactured several different types of battle droids which included sentries that were the smallest and most commonly produced that acted as a form of low-security guard. Their mechanical nature that they were often placed on guard duty where organic troopers would quickly tire and grow bored of as time passed on. Sith factories, palaces, shipyards and warehouses had handfuls of these sentry droids guarding them. For their operations, they were equipped with an arm mounted blaster.
In addition, these sentry droids were also placed on battleships, escort gunships and personnel carriers. During emergency situations, sentries were deployed in groups of six though otherwise were stationed at pre-determined sites or engaged in a pre-programmed patrol pattern.