Home | North America Office Contact Us: North America Office ATOP?offers?our clients a worldwide support. North America Office Placentia 377 Chapman Ave. Suite 235 Placentia CA 92870 Tel : 657 444-9015 Employees Jonas Zhang Tel : +86 15013815625 Email: Jonas@atoptechnology.com Gary Koelsch Tel : +1 949 254-4803 Email: Gary.k@atoptechnology.com Mike Bernatzki Tel : +1 650 255 9610 Email: Mike.b@atoptechnology.com Get the latest news from ATOP delivered right to your inbox Subscribe