The B4 capsule is ideal for live and orchestral applications. Blue's Bottle Caps are interchangeable capsules designed for any mission. The Interchangeable Capsule series contains microphones capable of providing a wide palette of tonal characteristics and pickup patterns to satisfy even the most discriminating tastes. The series integrates the best of Blue's discrete Class A circuitry with a unique and revolutionary system of interchangeable capsules that provide the engineer a wide range of potential tonal characteristics. This series is employed in the world's most respected studios, and is recognized by industry insiders as the world's premiere microphone system.