Chakra Blockers are in many forms and utilities. Though there are various techniques that deploy the use of sensory and a radar-like wave to disrupt others from actively moulding chakra there have been devices just before the Shoji Oppression as afterwards. Thus rendering the ability to use ninjutsu not optional. The forces of Shoji made the most use of the Chakra blockers in forms of columns and masts. These were powered by a combination of chakra and some electrical surges, being stationed in major sites.
Mobile variants of Chakra Blockers would be introduced as well during the Shoji Oppression. Smaller columns and masts that once activated would disrupt in a large - but still smaller than the stationary and larger variants - radius around them any active moulding of chakra. After the Oppression, however, these masts and columns would grow out of favour. Both because of the distrust for the use of the devices as expensive maintenance that they demanded. In various regions, there would be still interest in the Chakra Blocker technology. Leading to various types of smaller and more convenient modules, such as the Chakra Balls of the Kumogakure Guard, designed to help in arresting dangerous individuals who could or can use ninjutsu.