The circular geometric shape is the most standard design of the microchannel plate.
Circular MCP outer diameter ranges from 24.8 to 86.8 mm.
They can be manufactured in a non-standard form: with a central hole and different coatings such as CsI, KBr, MgO, Au and others.
MCPs with channel diameters of 3 to 15 µm are available.