You will find replacement heads for Arcitec models at saveroutlet.com. See link below. There is a picture on this page also with the installation instructions for these heads

http://shaveroutlet.com/norelco-philips-rq10-arcitec-replacement-heads-p-353.html

Norelco Arcitec electric shaver replacement heads is philips norelco RQ10 shaving heads