A quad OTA integrated circuit, made by a company called International Rectifier, to Roland's specifications. Roland used it to implement the voltage controlled filters on most of its 1980s-era analog synthesizers, including the Jupiter 4/6/8, the Juno series, the JX-3P, the MKS-30, and the first version of the MKS-80.
When purchasing, watch out for fake ones, made in China. The Roland name on it was accidentally printed as "Rolend". Another fake version has the IOS logo instead.