The byron by30102 portable wireless chime kits provide a choice of eight melodies and volume control it features self learning codes and will keep the code even when the batteries run out and are replaced the battery powered portable chime can be taken anywhere within the operating range it has a 90 94d b rating depending on the sound the chime requires 3 x c batteries not included the push requires 1 x cr2032 battery included operating distance by301 100m optional strobe light by302 200m