The Sennheiser MMD 935B is a cardioid capsule designed for use with various Sennheiser wireless handheld transmitters, including the SKM 100/300/500 G3/G4, SKM 2000/6000/9000, SKM D1/AVX, and SL handheld DW models (sold separately). It features a metal grille, an interchangeable system for different sensitivity levels and polarity patterns, and serves as a replacement for faulty or damaged capsules.