REAL PEOPLE, GREAT PRODUCTS, AMAZING SERVICE. Dimplex – Prism 74-Inch Built-In Electric Fireplace – Acrylic Ice Embers. Dimplex – BLF7451 – Prism 74-Inch Built-In Electric Fireplace – Acrylic Ice Embers. The Dimplex self-trimming electric firebox is a terrific alternative to wood or gas fireplaces, without the hassle. The Prism series…