Contact Contact Us Working hours Monday- Friday: 09:00-17:00 Hrs (Phone until 16:30 Hrs) We are here JPRM+5R5, SUMBER, Sumberagung, Kec. Klego, Kabupaten Boyolali, Jawa Tengah 5 Phone: 021 8263 1523 Email: office@osik.co.id | hrd@osik.co.id