Cambridge Sienna Fireplace Mantel with Electronic Fireplace Insert, White Full surround fireplace mantel constructed from MDF (medium-density fiberboard) - Assembly required Electronic, forced-air fireplace insert with log and flame effect Automatic thermal safety switch for Overheating protection Assembled mantel size: 33.9L x 10.4W x 37H Insert size: 23L x 5W x 17.1H