An EMP Blaster is an experimental T'au weapon that fires short-ranged rounds which explode in a small blast and generate an electromagnetic pulse (EMP) upon impact. EMP Blasters are issued exclusively to XV46-4 Vanguard Commander Variant Void Battlesuits.
Whilst the weapon's rounds do not physically damage foes, they send out powerful electromagnetic pulses that disable electrical wiring and all kinds of mechanical systems, playing havoc with the internal systems of armour and other vehicles and disabling them temporarily.
Sometimes, the EMP effect will even cause catastrophic failure in a system, leading to an explosive reaction for the unfortunate vehicle or robotic construct.
- Deathwatch: Ark of Lost Souls (RPG), pg. 124