Ceramic Heat Emitter, penetrating heat needed by cold-blooded reptiles Zero light emission - perfect for day or night Higher heat, longer life than light bulbs Deep down warmth that keeps reptiles at their active best. If reptiles could talk, they'd heartily endorse the satisfying heat output of Ceramic Heat Emitters. It's a heat which warms the pet rather than the terrarium, and leads to a higher level of activity and greater all-around health. The emitter generates no residual light, so it won't interrupt sleep patterns. The durable ceramic design outperforms incandescent and halogen heat bulbs in both heat output and working life. A tough ceramic shell protects pets and owners from accidental breakage.