CM & CP Audio Transducer and Indicator Buzzers CUI CM Magetic & CP Piezo buzzers provide audio alerts for a range of environments. These CUI audio transducer and indicator buzzers provide flexibility to design in an ideal tone or sound effect. CM & CP buzzers feature a small package size, a range of available IP ratings, and sound pressure level (SPL) up to 104dB. Applications include home appliances, automotive electronics, medical, safety and security, industrial, and office automation.