CBB21-B型电容器为无戌结构，用金属化聚丙燃膜作电介质/电极绕制而成，导线采用镀锡铜包钢线，使用环氧树酯密封在塑料壳内，外观一致性好，高频损耗小，绝缘电阻高，自愈性好，寿命长，广泛用于大电流以及高频，直流，交流和脉动电路中。
CBB21-B type capacitor are non-inductively wound with metallized polyproynlene film as the dielectric/eclectrode with copper-clad steel leads and encapsulated in a plastic case sealed with epoxy resin , the identical outer insulation resistance, long life due to self-healing effect. widely uesd in high frequency, DC, AC,and pulse circuits.