The light weight of a Prelite plenum box means that, unlike a metal version, it requires only one person to lift it up to ceiling height.

The Prelite Plenum box can be quickly fitted just by sitting it on top of the ceiling grille.

Being pre-insulated, the Prelite plenum box needs no lagging operation.  Simply fit by screwing through L-shape plates into a proprietary grille.

Additional support is rarely needed, unlike sheet metal plenum boxes which may need support from the soffit.