Imperial I-class and Imperial II-class Star Destroyers each carried two ISD-72x generators/sensor arrays.[1] The shield projector vanes were positioned in a crown formation around the command tower's sensor globes.[1][2] The vanes projected both ray and particle shields and were scattered along the "crown", one function per vane.[1]
This deflector shield required a massive amount of energy, drawn from the Star Destroyer's main reactor via power generators located deep within the command tower.[1][2] Thick armor protected the sensor banks from impacts, but the globes were vulnerable to suicide attacks from small starships[1] or missile weapons such as concussion missiles or proton torpedoes from starfighters. [6]
It was developed to reduce the need for secondary equipment aboard Star Destroyers, and replaced the Om-Thaim shield generators installed on earlier Destroyer models.[1]