The brushes are held by a fake "charger tap" so heir type and diameter dos not matter.The support is meant to be held on the wall with glue or double-sided tape (foam tape / mounting tape). But you can also drill in it if you want to...There is a hole at the front so the eventual water and toothpaste drops on the sink, not along the wall (thanks to a groove on the underside).Two models are provided, single and double.I also provide source files (SolidWorks 2014) and STEPEnjoy!