R-EAU Linemasters were supply and armament droids deployed by the Rocket-Jumper Elite Advance Unit prior to the Great Droid Revolution.
Linemasters that survived difficult campaigns often became platoon mascots of their units. Some Linemasters, but not all, had integrated rockets.
These droids served as the basis for the Juggernaut war droid, but would be forced into retirement following the Great Droid Revolution (a special provision advocated by the Rocket-Jumpers prevented their dismantlement, however).
