XP 820 is a unique, slow-release ear tag for cattle thatis the first ever tag to contain abamectin, a highly activemacrocyclic lactone that has never been used before oncattle in the USA plus the synergist piperonyl butoxide.XP 820 is particularly effective against horn flies, including strains resistant to syntheticpyrethroid and organophosphate insecticides. Controls Horn Flies for up to three monthswith one tag per head and up to five months with two tags per head. Reduces Face Flieswith two tags/head.