| 主权项 |
1. A hand held device comprising:
a) a head unit; and b) a handle comprising a docking member for connecting to said head unit, and a gripping portion positioned distally away from and said docking member, wherein said gripping portion comprises:
i) a substrate retaining member forming a receiving region;ii) a substrate removably retained by said substrate retaining member in said receiving region, said substrate comprising a top surface and bottom surface, opposite said top surface, wherein said top surface comprises a series of overlapping rings. |
