The GridFusor™ is specially designed as a replacement for ceiling tiles in a standard drop ceiling grid. Two GridFusors™ will easily fit into a standard 2′ x 4′ grid opening. The GridFusor™ is made from EPS (expanded polystyrene) so it’s light enough easily mountable on walls, ceilings, etc. without the use of damaging adhesives or massive mounting holes while still providing excellent diffusion characteristics.