Our 420 Series Neodymium Continuous Duty Speaker is a perfect choice for tight fitting locations where space or weight is premium consideration. The 11 ohm, the unique voice coil is oven baked on a high temperature and sealed with a special coating to withstand extreme temperatures and environmental conditions. The voice coil is further protected with a special magnetic cooling liquid that fills the voice gap and provides a thermal path. Lightweight, low profile compression driver is the lightest (56% less) and the lowest profile (31% less) of the conventional ainico based compression drivers. Meets SAE Class A requirements.