From their announcement:
a bulky, armoured track unit which mounts a powerful antomantic reactor. The Rapier is often armed with a powerful quad lascannon known as a laser destroyer. This has become synonymous with the Rapier Armoured Carrier itself, and the Graia Pattern Rapier Laser Destroyer is perhaps the most common design of this potent anti-tank weapon.
Designed by Will Hayes, the Graia Pattern Rapier Laser Destroyer is a finely detailed full resin kit, which contains parts to build optional Cadian crew, and can be used in several different armies. You can download experimental rules for the Rapier Laser Destroyer from the Forge World website.