Chimerro Cube Missile Launcher

"The Chimerro possessed either a single Hunter-Killer Missile Launcher tube attached to the turret and an automated reloading system or a rack of 8 cubic box Missile Launchers on the top of the rear hatch. While the former variant of the Chimerro still retained the top hatch, it was difficult to keep it in proper working order, so it was rarely used. The second variant of the Chimerro was more common in Imperial service as its Missile Launcher was useful in providing combat support for Imperial Guardsmen attacking strongly fortified targets."
Warhammer 40k Wikia

You will require a Chimera tank for this conversion. The missile pod is supported by a small plastic pin, which can be cut to desired height. I recommend the White and polished print, the cost and detail of the Frosted Ultra is not often worth it.