Javelin attack speeders are both rare and highly valued, utilising a range of antigrav impellor technologies so esoteric that some amongst the Mechanicum regard them with overt distrust.
Regardless of their technical complexity, these hovering vehicles are fast, highly manoeuvrable, have an extended operational range and – perhaps most importantly – can carry a heavy payload of weapon systems, qualities which keep them in high demand throughout the Legiones Astartes.