Signature Master is designed as a monitoring reference for the most demanding recording studios. The 40mm titanium-mylar diaphragm delivers similar fidelity to the well-known Edition Series reference headphones. Ultrasone uses S-Logic 3's natural surround sound and ULE (Ultra-Low Emission) radiation reduction technologies to ensure a comfortable and safe listening experience. Made of merino sheepskin and durable plastic with a gold nameplate, these headphones meet the needs of long-thinking audiophiles.