B1-series rocket battle droid were B1 battle droids equipped with jetpacks. They were used by the Trade Federation and later by the Confederacy of Independent Systems during the Clone Wars and would be the predecessors to the B2-RP Rocket Droid.
When Jedi Master Plo Koon's Venator-class Star Destroyer Triumphant was attacked and destroyed by General Grievous' Malevolence, several B1-series rocket battle droids were deployed in a Droch-class boarding ship to seek out and destroy all survivors/witnesses of the Triumphant's destruction. Armed with cutting equipment, in addition to the standard blaster, these droids attacked the life pods that had been jettisoned from the Triumphant, breaching the windows and killing the survivors the vacuum of space. After killing all those aboard Pod 1977, they moved on to the life pod which housed Plo Koon and his men. Plo Koon, however, was waiting for them, armed with his lightsaber. He and clone troopers Sinker and Boost fought off the droids, before Master Plo severed the Separatist boarding craft's hold on the pod, and sent them hurtling off into a piece of debris, causing a violent explosion, and the destruction of the rocket battle droids.