The Sennheiser MZW 1 (article 004839) is a foam windscreen for the handheld transmitters of Sennheiser's evolution wireless range - specifically the SKM 100, SKM 300 and SKM 500. It slips over the microphone head to cut wind noise and breath pops (plosives) when the microphone is used outdoors, close to the mouth, or on stages with fans and air conditioning, and it also keeps the grille cleaner and helps protect the capsule from moisture. It is a practical spare for presenters, MCs, sports commentators and bands that share handheld radio microphones. Sennheiser lists it at 30 g; it is a dark grey/black acoustic foam as shown in Sennheiser's product image. Sennheiser's page states that no battery is included (it is a purely passive accessory). Check the fit before ordering if you use Sennheiser's newer EW-D digital handheld transmitters, as Sennheiser lists only the SKM 100/300/500 for this windscreen.