The Pin-27 is a 2 x 18 pin Mill-Max male to male adapter. It is used to make connections between the HS-27x headstage series of Electrode Interface Boards (EIB) and the HS-27x headstages.

The Pin-54 is a set of Mill-Max male to male adapters consisting of two 2x9, one 1x14 and one 1x16 adapter. It is used to make connections between HS-54 headstage and the EIB-54K Electrode Interface Board (EIB) generally used with the Kopf/McNaughton Microdrive.